A Comprehensive Review on Metal Matrix Composites for Railway Applications
Mohit Hemanth Kumar*
Department of Mechanical Engineering, Alliance College of Engineering and Design, Alliance University, Karnataka, India
Sanjay Mavinkere Rangappa and Suchart Siengchin
Natural Composites Research Group Lab, Department of Materials and Production Engineering, The Sirindhorn International Thai-German Graduate School of Engineering, King Mongkut's University of Technology North Bangkok, Bangkok, Thailand
* Corresponding author. E-mail: [email protected] DOI: 10.14416/j.asep.2022.03.003
Received: 16 December 2021; Revised: 15 January 2022; Accepted: 3 February 2022; Published online: 11 March 2022
© 2022 King Mongkut’s University of Technology North Bangkok. All Rights Reserved.
Abstract
The railways produce the backbone of all passengers, transporting goods and economies. Railway compartments play a critical role in safety and track performance in rail transportation. Composite-based sleeper is developed into an adequate substitute for recovering the existing steel, concrete, and specifically timber sleeper in heavy- haul rail and mainline networks. Composite sleeper methodologies are earlier abundant, but they have captured restricted acceptance from the railway industry. Presently, the composite sleeper methodologies are significant, ranging from sleepers created with recycled components initiating from construction waste, rubber, and plastic.
While these recycled components based sleepers are lower price, the primary issues of utilizing this these kinds of sleepers are their limited dynamics, stiffness, strength characteristics that, in most conditions, are incompatible with those of conventional timber, steel, or concrete sleepers. The essential for novel material with standard features have paved the path to developing and emerging components from metal matrix composites. Parts that acquire prescribed characteristics, like including strength, good toughness, higher resistance from corrosion, and wear in their fibrous medium are favorably reinforced with fundamental metal to fabricate metal matric composites. In this review paper, the components of railway systems, different types of fabricating metal matrix composites, issues while conducting experiments, sustainability, life cycle assessment, and waste management are explored together with the present complexities opposing their whole market avenue.
Keywords: Aluminum metal composites, Fabrication techniques, Life cycle assessment, Railway components, Sustainability
1 Introduction
Due to the continuous development of population, transportation systems invariably have a higher demand in different industrial sectors. They will permit economic and social enhancement over the upcoming years [1], [2]. In recent years, world environmental problems have attained the main interest. Ozone layer depletion, pollution from acid rain, and global warming tend to the destruction of a vast amount of
species. Also, ecological issues, like such as decreased forest cover, desertification, and water pollution are extensive in developing nations. This creates it critical condition for human beings to shield the world's resources. Meinhausen et al. [3] observed that half of the greenhouse gas emissions (consisting of land utilization) in 2014 derived from Europe, the United States, and China are the largest shore holders. Hence, these nations are answerable for developers to decrease carbon emissions. These environmental problems of
the industrial age have constrained many international accords to be endorsed with the mutual target of restricting the global temperature improves to below 2 °C [4]–[6]. Afterward, the arrival of the current year, a considerable amount numbers of fabricating companies have been the primary reason behind the pollution from the environment. Crisis of energy, scarcity of resources, and degradation of environmental conditions have propelled attention to the urgency of enhancing resource usage, sustainable development, and environmental protection. To date, the benefits of higher strength composite laminates play an essential role in engineering and technology.
Furthermore, the environmental issues affected by the recycling, waste of materials, and higher energy consumption for composites could be underestimated and ignored [7]. Recently, the utilization of new kinds of composites for railway sleepers has attained broad spread in the world market, specifically in the fiber-reinforced based urethane. Laminates have been established to be a novel material for developing bearers and sleepers in railway crossings and switches that are relatively sustainable and free from maintenance in terms of environmental aspects [8], [9]. In various conditions in practice, the provisional utilization of composites is practically needed to alleviate the critical formulation of the turnout scheme, like for example redistribution of stress, environmental resilience, and resistance from the load.
Amplifying the decreased periods accessible for track maintenance is the total weight of the rail transports themselves. There is a present direction towards incrementing the importance of rail transports [10], possessing the influence of incrementing axle forces. Heavyweight trains, functioning under higher density and speeds, have improved loads on the rails.
This outcomes developments in rolling contact fatigue and rail wear postures significant exposure lead to reliable and safe rail transport. The lightweight of the rail transports is essential for decreasing this damage and consistent as a pivotal enabler in reducing energy consumption [11]. The addition of polymer-based laminates utilized for structural parts is one term for offering lighter rail transports. The highest ratio of the weight of rail transport is assigned to the rail compartment, presence of 41% of the weight [12]. The compartment is a chassis that includes the supports and wheelsets of the rail transport body. The wheels
and axle present the bulk unsprung weight that offers progress to track shock damage. A steel axle consists of 198 kg of an all-around wheelset by weight, and this constituent has a significant possibility of a lightweight structure. Moreover, the axle is subjected to rotating and loading flexural fatigue throughout its lifecycle.
The light design of the unsprung weight is sent from the NETGEAR project assigned under the railway scheme supported by EU Horizon 2020 [13].
The appropriate material selection is a deliberating building issue to the researcher. Whatever is performed carefully can be the efficient utilization and best possibility with the considerable activity of the scheme.
The components are required to operate as per the owner's requirements and should hold the appropriate characteristics in the workplace throughout the time frame. Present investigations aim to gratify the market where the indications are ever-improving in quantity.
The market requires progressively efficient vehicle generating power, bother-free vehicles, increasingly agreeable, quicker, progressively lighter, and minimized equipment and machines. Most of the built components can consist externally of a outperform or stretch meet structure particulars that would not be anticipated before two years. The present constituents are disclosed to progressively extreme working cases, more stress, and incrementing loads in a field never accomplished.
The metal matrix composites are highly competitive constituents for many applications with a combination and choice of attractive characteristics. The metal matrix composites acquire the challenging aspects of the ceramics and base component. Hence, they have higher modulus and strength, lower density, higher toughness and flexibility, and combinations of better characteristics of both composites [14].
Therefore, incorporations generally enhance the features of the base component. These combinations of desired characteristics can hardly be collected with a single constituent. Based on the trait's needs, various reinforcements and base components can be selected for a specific application. Base constituent sometimes is observed as a matrix. Aluminum-based alloys have excited more attention as a base constituent [15]. They acquired characteristics like such as good stability under higher temperatures, excellent resistance from wear, capability to resist deformation, higher strength, and lower weight is given volume and drawn into wires. The attention for enhanced, developed and
better materials in the sectors, especially like aviation and vehicle advised a fast development of metal matrix composites [16]. These laminates have become crucial for advanced subsystems and schemes [17]. Ceramic incorporation outcomes in higher strength and hence is applied together with another component to create hybrid materials. The secondary incorporations curtail both prices of the hybrid constituents and their mass [18].
The achievement of powder metallurgy to fabricate metal matrix composites has been compared from Harris [19] with those manufactured from other manufacturing techniques. The manufacturing of metal matrix composites through operating the melt has been attained because of its lower prices, whereas the limitation is a separation of dendrite and agglomeration.
Moreover, higher molten metal temperatures affect undesirable chemical reactions under the interface.
Likewise, using the stir casting technique to fabricate aluminum metal matrix composites reduces the price, as it is simple and easy to conduct [17], [20]. Waku and Nagasawa [21] established that solid components are sub-standard compared with metal matrix composites in numerous prospects. Methods to produce metal matrix composites and ceramics are studied from Rosso [22]. Different other related characteristics, future scope, and utilization of the applications have been assigned. Manna et al. [23] engaged the melt stirring method to manufacture Aluminum-Alumina metal matrix composites. Isotropic characteristics of the fibers have been applied as reinforcement in this manufacturing technique. To attain good mechanical characteristics of laminates, uniform comprising of two (ceramics and metal matrix composites) is the pre-requisite. The interface, reinforcement, and matrix are the three primary parameters that influence the complete performance of metal matrix composites [24].
Enhanced characteristics are attributable to correct reinforcements in the matrix. The utilization of reinforcements in the base metal is a continuous region such that its features were improved. Different methods are manufactured for the creation of metal matrix composites. The stir casting process is noticed as an unquestioned method for explaining its kind features.
Metal matrix composites offer extra opportunities for further extensive utilization of components by regulating their productions to choose the essential
characteristics under different work locations. The scheme of composites with accurate characteristics can also apply finite element modeling schemes.
The features of composite laminates confide in their grain size, manufacturing technique, components, and their respective morphology. Thus, this paper reviews the different influences of parameters, like including fabrication technique, reinforcement type, material's properties, and life cycle assessment for the development of railway applications. A collection of nano- and micro-scale constituents is produced for various base components as matrices. The headways described with the blend method have supported developing new laminates and reducing the explicit features. Many observations were abstracted on aluminum matrix laminates, given passion for lightweight laminates to overthrow heavier steel components.
2 Primary Components of Railways
Steel is one of the primary components within the railway structure. It is applied in fastening and rail schemes in the railway sectors. Moreover, steel is one component that has the most effective recycling rate. Steel can also be recycled for producing new components again and again [25], [26]. Generally, it is observed that steel has a mass recovery parameter under 98% with a residue of 2%.
Furthermore, it is also observed that steel exhibits a 4% gap of mass recovery parameter. The cause is that the union of European railway industries technique has been detailed as a potential evolution depending on ISO 22628 standard. In general, around 85% of steel is recycled from the steel industry, and this quantity is predicted to increment to 90% in the year 2050 [27].
The damage of metal components possesses primarily because of poor methods and quality of materials.
Railway sub-ballast and ballast are applied to produce the infrastructure of railway tracks for distributing and performing loads. As the bulk of components in railway turnout, Accumulates accumulates played an influential role in influencing the recovery and recycling. It has been observed that construction parts have a 93% recycled concentration. In addition, Indraratna et al. [28] predicted that around 90% of components could be recycled and another 10%
contains cemented components. Possessing endured
cyclic loading of sub-ballast, ballast, and heavy trains reduce due to the throng acceptable filler transfer within the ballast bed and complete the gaps between the nearby grains. The impurities, such as fragments and other sundries, result in wastes [27].
2.1 Railway axle
An axle is produced with the aiding bearings either inboard or outboard the wheels. As the track length is located, an outer part of the bearing system can achieve the highest decrement in weight. It characterizes a plain, more extended shaft portion adequate for replacing carbon fiber reinforced polymers. As an outcome, an outer part of the bearing scheme is selected in a recent investigation. The axle was possessing an inner board bearing system usually affects the overall weight of the compartment [29] and would also be advantageous from the multifunctional mechanisms. A trailer compartment characterizes the most accessible railway axle system with no additional drive components seated on the shaft portion. However, brake discs can also be attached either to the outer part of the wheels or wheel webs. In general, the railway axle for a trailer compartment, structured for an outer part, is present in Figure 1. The main characteristics of the axle are the central plain shaft part, bearing, and wheel seats. The weight of this axle was 400 kilograms.
The fundamental standard for the structural scheme of an outer railway axle is EN 13103-1 [30].
Conformity with the force conditions within this standard is observed from the structural hybrid metallic composite axle assembly as observed in Figure 2. The carbon fiber reinforced tube contains carbon fiber as reinforcement, higher modulus within the epoxy
polymer. The axle strength is controlled from the fatigue characteristics where the service life of the axle is more than 30 years [31].
This relates to a higher quantity of load in the range of 109 reverse flexural cycles. Four-point flexural is the primary force condition incorporating torsional force under dynamic wheelset hunting and braking case.
The stiffness of the axle for the carbon fiber reinforced polymer tube is essential to conceal the development of crack within the polymer while restricting the deformation of the bearings and drive components for powdered axles. A higher range of stiffness is necessary to limit the strain within the polymer.
Microcrack initiation is constrained during this lower strain case, where the vast cracks could not produce.
Dynamic cases contain operational frequencies with vibration and shock limits. The old part can tend to rail crease if exposed, where the latter part is endured when the rolling of wheels over the irregularity of track. The first signification of the level of vibration of the axle can be observed in the BS EN 61373 standard [32]. Shock loading influences are generally appraised under wheelset assembly-level via a roller rig as a component of the laboratory testing scheme.
The dynamic testing cases stated for a steel axle and assumed approximate to supply these to the carbon fiber reinforced polymer tube and establish similar active testing cases. This method permits the bearing solution and existing wheel to be controlled. Moreover, the inner part of the wheel seat, an expansion is incorporated for the addition into the carbon fiber reinforced polymer tube containing a component to term the overall length of the axle. The structure of the extension influences the characteristics of the adhesive network.
Figure 1: An outer part bearing trailer axle with general dimensions [36].
Figure 2: Structure of unoptimized structural hybrid metallic metallic-based composite railway axle principle [36].
2.2 Different layers of coaxial skins
Conformity with the secondary need is attained via coaxial skins combined with the structural hybrid metallic composite railway axle assembly. These skins are examined in the primary design scheme as presented in Figure 3.
Indeed, other skins with identical formulations could be added to the overall strategy. Estimating modification in the integrity of the structural hybrid metallic composite railway axle assembly will be needed for product certification and risk moderation.
In this context, the general form of a quantitative inspection capacity will assure that the asserting thirty years of service life can be obtained. Non-destructive testing is favored for examining with ultrasonic testing, generally applied for hollow steel axles. For a hybrid metallic composite axle, depletion of the ultrasonic testing source is an interest as damages may not be appreciable. However, procedures within the bore of the axle exhibit intricacy in sensing from ultrasonic waves. As a substitute, structural health monitoring layers in the medium of strain sensing element could offer a continuous assessment of the integrity of the carbon fiber reinforced polymer tube. Also, generalized utilization of leaky optical fibers along the chain lines could offer ultra-violet healing of the adhesive network and the possibility for bond decomposition at the end of the product life cycle. An optical, trackside part of structural integrity for the hybrid metallic composite axle is suggested via shackle equipment. This constitutes a stressed cable that is protected at one part of the axle while being attached to a load gauge on the other part.
The indicator is fixed within the butt axle part, observing the rope tension. A decrement in tension (signified as
red or yellow on the indicator) would help examine whether destruction had happened to either the connection between stub axle and tube or the carbon fiber reinforced polymer tube. However, the harness would be developed to avoid disengagement of the wheel should possess fatal damage to the axle.
The performing temperature for the axle ranges between 40 and 70 °C [33]. Finite disclosure to a higher temperature range using cleaning fluid, heat radiation, and disc braking utilizations claim a glass transition temperature for the carbon fiber reinforced polymer tube in addition to 100 °C. The railway need for toxicity, smoke, and fire characteristics was appealing and explained in the EN 45545-2 standard [34]. This norm is a problem for thermoset-based polymer, specifically when performing in enclosed regions like tunnels. The acceptable operating condition of the carbon fiber reinforced polymer tube is in the range of 120 °C. Whereas the standard operational cases can be observed, shielding must follow the abovementioned requirements. Minimal, smoke, and fire maintenance methods include conserving the carbon fiber reinforced polymer tube surface from a higher range of temperature modification via insulation or cordially distributing heat from the generalized heat source. The insulation is preset in blanket or mat form, consisting of ceramic-based fillers. Thermal insulation is managed from an aramid fiber in phenolic polymer or aramid honeycomb as an external glass skin.
Instead, a unidirectional carbon fiber epoxy composite has a better thermal conductivity in the horizontal direction. These fillers could be applied for structural characteristics and offer axial heat distribution along the carbon fiber reinforced polymer tube to the metallic stub axles.
The impact of ballast is a problem for steel axles.
Also, higher regard for hybrid metallic composite axles as they tend to delamination can accelerate the development of crack in the matrix and breakage of fiber under fatigue load. Generalized damage may happen while projecting maintenance. Presently, a glaze termed LURSAK fabricated collaboratively from Akzo Nobel Aerospace and Lucchini RS, broadly applied for ballast shielding [35]. This result equitably may be relevant to a hybrid metallic composite axle. A different method is to engage a layer of rigid reinforcement, like such as Dyneema or Kevlar. This would be improved via a thin foam below the stable Figure 3: Cross-section of a design principle for the
hybrid metallic metallic-based composite railway axle with axial and coaxial skins [36].
support and could offer a lightweight, convenient region around the structural carbon fiber reinforced polymer tube.
The outer part of the tube played as a chemically inactive shield against corrosive substances, like such as degreasing lubricants or fluids applied on the railway.
This depends on the same hypothesis to utilize an outer part of nearly higher voltage-covered power cables to shield the environment and mechanical resistance.
Significantly, this shield should be closed to avoid moisture access to the internal layers, specifically the structural carbon fiber reinforced polymer tube. The ultra-violet shielding to prevent long-term plastic decomposition could characterize this skin. A copper wire mesh within the skin portion offers electromagnetic compatibility to avoid conflict with the structural health monitoring device. Finally, this layer's intensity could correspond to distinct axle masses, fabricate date, and care of indicators [36].
3 Fabrication Methods of Metal Matrix Composites 3.1 Liquid state processing
The liquid state processing method contains composting, laser melt-particle injection, ultrasonic-assisted casting, squeeze casting, stir casting, thermal spray, and infiltration technique. In casting, the base metal is heated over the melting point, and the reinforcement elements are added to the molten constituents with the help of mechanical mixing. During this technique, automatic mixing in the heating furnace is critical. It is a very flexible, cost-efficient, and simple approach to the weight production of metal matrix composites. Cooling rate modified from the non-uniformity of the components and surface to the center is the primary limitation of this technique, along with lousy wettability of reinforcement and base metal [20]. Aluminum- titanium oxide and aluminum-titanium di-boride nanolaminates with different volume proportions of reinforcements manufactured from Akbari et al. [37]
using stir casting technique. The uniform particle dispersion and higher mechanical characteristics achieved in aluminum-titanium di-boride laminates than aluminum-titanium oxide laminates and nanofillers were partially obtained in the base metal. The titanium- di-boride nanofillers exhibited good wettability than titanium oxide particles. Aluminum reinforced with
titanium di-boride showed evident advancements in wear and hardness resistance. The porosity and eliminated nanofillers quantity improved with incrementing concentration of the reinforcement. With incrementing normal force during the wear testing process, the coefficient of friction and wear rate of the reinforced specimen reduced and improved. The severe and mild wear accomplished under oxide layers and worn surfaces were identified.
Furthermore, incorporating nanofillers reduced the count and depth of grooves on iron trace, and worn surfaces were identified in the trashes of wears. Dou et al. [38] were manufactured 20 wt% of boron carbide in aluminum alloy 6061 laminate from the stir casting process. In contrast, the wear and friction characteristics of the laminate were obtained by fluctuating the applied force, heat treatment, sliding velocity, distance, and time taken. At the beginning of the wear experiment, the weight loss progressed with force, and time was taken, reducing marginally with increasing the sliding velocity. At the period of 1200 second time taken, applied force of 30 N, and sliding speed of 240 rpm, the coefficient of friction and weight loss increment noticeably, and severe delamination wear exists. The highest wear resistance of laminate was collected from 1 hour of solutionizing under 5500 °C followed by aging under 1800 °C for 15 h assigned to improved interface bonding between boron carbide reinforcement and base aluminum and precipitation of magnesium silicate.
The main drawback of the stir casting technique is that the fillers sink to incline or float on the base melted metal after wetting because of the density differences between the reinforcement fillers and base metal and outcomes in non-uniform distribution. Two-stage incorporation of fillers may prevent the accumulation and clustering of the fillers. Aluminum-boron carbide laminates with 7 and 5 wt% of fillers under 7500 °C manufactured from Auradi et al. [39] with flux using two-stage incorporation melt stirring technique to enhance wettability and to prevent accumulation of boron carbide fillers. Uniform dispersion of boron carbide fillers in the aluminum without accumulation, enhanced compression, tensile strengths, and hardness of the laminates were examined.
Das et al. [40] manufactured aluminum alloy 6061 reinforced with silicon carbide and boron carbide hybrid laminates from the traditional stir casting
technique. Wear rate of laminates comparable to the applied force. Furthermore, the rigid ceramic fillers decreased the contact area between both areas, which resulted in the decrement of friction coefficient under higher sliding velocity. The abrasion, adhesion, and oxidation were assertive wear. Ramakrishnan and Padmavathi [41] manufactured aluminum-silicon carbide-multi-walled carbon nanotubes nanolaminates from stir casting technique with higher dry abrasive wear resistance when compared with single aluminum- silicon carbide laminate. The specific wear rate was reduced with the addition of multi-walled carbon nanotubes. Aluminum-silicon carbide exhibits higher hardness than aluminum-silicon carbide-multi walled carbon nanotube, furthermore among the hybrid laminates, hardness increment with improved hybrid proportion.
3.2 Solid-state processing
To overcome the drawbacks of liquid-state processing, metal matrix composites fabricated from solid-state processing techniques below the melting temperature of the base metal. The solid-state method contains friction stir processing, cold spraying, spark plasma sintering, diffusion bonding, high-energy ball mill, and powder metallurgy. In the process of powder metallurgy, fine particles are blending and mixing, degassing in the vacuum, and then determined in favored structure followed with the sintering in a regulated atmospheric condition. Powder metallurgy is approved to fabricate complex structured precision constituents with higher structural and mechanical characteristics and uniformity. Aluminum-based laminates incorporated with ceramic fillers are correspondingly simple to process and practically isotropic compared with fiber-reinforced laminates. The powder metallurgy technique is economical for complex component fabrication with lower subsequent machining operations, dimensional accuracy, minimum loss of scrap, and higher strength. Still, powder metallurgy requires costly alloy fillers and holds complicated process procedures, thus may not be adequate for weight development. Aluminum alloy reinforced boron carbide manufactured from Zhou et al. [42] from powder metallurgy method at hot-pressed temperature 620 and 520 °C to study the role of micromixing of copper constituent in aluminum-boron carbide laminates. In
the 560 °C hot pressed laminate, the Q region was the crucial copper-restrained precipitates. In the 620 °C hot-pressed laminate, the reinforcement-base metal reactions fabricate MgB2 and Al3BC was isolated at the base metal-precipitates interfaces and increment the precipitates nucleation. Various factors, such as compact pressure, green density, sintered density, and volume proportion of the reinforcements can control resultant metal matrix composites. Balamurugan et al.
[43] appraised the influence of sintering temperature, time, and compaction pressure on wear and mechanical characteristics of fly ash/ copper laminates fabricated from powder metallurgy method with 5 and 10 wt% of precipitator fly ash collected from the thermal power station, Tuticorin, Tamil Nadu, India.
High energy ball milling is also a powder processing technique, that employs higher energy influences from higher-frequency of hard material balls in attrition mill for mechanical alloying of processed particles. Powder fillers cemented between highly kinetic colliding balls that affect fracturing of premixed powder fillers, re-welding, and intermittent deformation subsequent in particle distribution in the delicate base metal. Ceramic rigid fillers incorporated in base metal to fabricate laminates with improved hardness, strength, and resistance from wear. This technique prescribes a regulated atmosphere to avoid powder from atmospheric reactions. It is not adequate for weight production and is also a time-consuming technique. The dry storage of spent pivotal requires higher strength and lower price boron carbide-aluminum neutron absorber components with higher stability under higher temperatures. Using the powder metallurgy technique, Zan et al. [44] produced aluminum alloy- boron carbide laminates by varying hot-pressing temperatures. With incremented hot-pressing temperatures ranging between 560 and 630 °C, the outcome of the interfacial reaction in the fabrication of Mg(Al)B2 and Al3BC components and the mechanical characteristics of the laminates were improved. The tensile properties of the specimen hot-pressed under 630 °C were 59% greater than that of hot-pressed 560 °C strength under both elevated and room temperatures assigned to blockage of dislocations motion from Mg(Al)B2 nanofillers.
Furthermore, the mechanical characteristics of the specimen hot-pressed under 630 °C were substantially annealed at 400 °C for 8000 h. Akbarpour et al. [45]
manufactured nano-shaped copper and their respective composites from hot-press and high-energy mechanical alloying processes. Ultrafine grain base metal with uniform distributed fillers and around fully dense laminates recorded. Hybrid micro and nano silicon carbide fillers in the copper matrix resulted in improved compressive strength, lower coefficient of friction, and wear resistance compared with micro silicon carbide fillers. The addition of hybrid fillers reduces 61% base metal grain size and improves 35% of compressive strength and 53% of wear track width compared with the nano-shaped copper specimen. Hybrid silicon carbide reduces plastic deformation, cracks, pits production on the worn surface. In the spark plasma sintering method, the heating is carried out from spark discharges between the gaps in the fillers that energized self-heating and filler surface manufactured between the fillers. Spark discharge fabricated from a pulsed direct current through electrodes from top and bottom punches of the die. The spark plasma sintering method is affirmed to enhance material characteristics, shrinkage under lower processing temperature, efficient formation of the interface, dense bulk material, lower sintering time, and higher heating rates. Al-Aqeel et al. [46]
produced cobalt-tungsten carbide laminates with 12 and 9 wt% reinforcements and as earned ball-milled 10 nm-sized tungsten carbide and 3.5 lm sized tungsten carbide from consolidation using spark plasma sintering technique under 1300 and 1200 °C with the period of 600 s, 50 MPa of pressure, and higher vacuum.
The grain development inhibitors Cr3C2 and VC were incorporated each 0.6 wt% to laminates, restricted grain sizes to 71 nm with around full densification, fracture toughness of 9.23 MPa m1/2, and mean hardness of 1592 Hv 30.
3.3 Reactive processing
In ex-situ techniques, the reinforcement is produced differently before laminate production. The ex-situ techniques compose complex steps and equipment and are essential to expensive reinforcement components, outcomes in higher managing prices. The substitutional cost-efficient in-situ processing techniques include chemical reactions between different components that expand thermodynamically stable addition in the base metal. Homogeneous distribution and good wettability of the fillers and their possibly lower price produce
in-situ processing techniques more advantageous when compared with the ex-situ method. In the in-situ manufacturing process, one reacting component is commonly a constituent of the molten base metal, whereas another component incorporates gaseous regions or fine powder fillers. Selvam et al. [47]
manufactured aluminum alloy reinforced with titanium boride and alumina hybrid laminates from an in-situ H3BO3 and titanium fillers with melted aluminum base metal via regulated environment electric stir casting method. Cubic and hexagonal structured titanium di-boride and spherical structured alumina produced under 950 °C temperature from refined aluminum metal and aluminum-titanium-H3BO3 reaction particles between 14 and 103 lm with 0 to 15 wt%. Uniformly dispersed fillers with better interfacial bonding were recorded. The thermodynamically stable titanium di-boride and alumina nanofillers enhanced the tensile strength and microhardness of the laminates, 287 MPa and 122 HV, respectively, with the reinforcement of 15 wt%. Selvam et al. [48] produced aluminum (AA 7075)/ zirconium di-boride metal matrix composites with the in-situ chemical reaction of K2ZrF6 and KBF4
inorganic chemicals to aluminum melt from the stir cast technique and examined the influence of temperature on the dry sliding wear characteristics of produced laminate. Zirconium di-boride fillers cultivated the aluminum base metal grains and improved the wear resistance under higher atmospheric temperatures.
The wear characteristics of metal matrix composites improved with the incremented zirconium di-boride concentration in the base metal. Under the higher temperature range, the zirconium di-boride fillers exhibited thermodynamic stability without degradation.
Moreover, the traditional fabrication technique of metal matrix composites, certain of the new methods are CIP-HIP sintering procedure, sputtering, and molecular level comprising technique. These techniques assure excellent impurity regulation, a clean environment, and better homogeneity. The reinforcement materials, base metal, fabrication route, proportion of the reinforcements, different types of reinforcements, and their size dominate metal matrix composites' final characteristics [49].
3.4 Microwave sintering
There are substantial fundamental differences between
micro-wave and traditional heating techniques. In the old condition, various heating components, fuels, and refractory constituents are needed, and a higher range of temperature should be operated for a tremendous amount of time to accomplish the sintering technique [50]–[52]. Besides, the transfer of heat between substances through conduction, convection, and radiation expands the waste of energy. Furthermore, to avoid the thermal grade, the heating rate should be slow or else the time of sintering increments and irregular grain development [53], [54]. Separately, in current condition, most of the furnace's environment, like walls and air, are not associated straightly.
Similarly, the energy is shifted to the specimen straightly and affects fast internal volumetric heating [55], [56]. In this condition, consumption of energy and sintering time could be decreased 10–100 and 10 times, respectively [57], [58]. Furthermore, the power of the micro-wave field among fillers is a maximum of 30 times higher than the external field tends to the improvement of surface ionization [59]. Subsequently, the ion kinetic energy and ionic diffusion rate improve in the whole region, specifically under grain frontiers. These outcomes produce more uniformly dispersed denser bodies and grain sizes [60]–[62]. Certainly, ionic diffusion between fillers is an evaluating parameter in densification rate that can be promoted from the micro-wave process [63], [64]. The micro-wave sintering characteristics are shortly explained. Micro-wave heating could also produce an essential thermal grade in the sample under instabilities affect and higher temperature. Investigators examined a hybrid sintering technique, including a two-dimensional heating process, to defeat this issue.
Components with higher dielectric losses under ambient temperature are essential (generally silicon carbide) [65]. In principle, they are applied as an infra-red absorbing resource known as a defector. By consuming lower micro-waves under lower temperatures, defectors shifted the developed heat to the specimen through customary conditions [50], [66]. Owed to this innovative technique, it can simply sinter all-metal, non-oxide, and oxide ceramic components [67].
3.5 Laser-assisted additive manufacturing
Upcoming research should also study the appropriateness of other developed reinforcement components in
laser-endorsed additive manufacturing of metal matrix composites. Furthermore, different kinds of reinforcement, like such as fibers, whiskers, and platelets have distinct incorporating principles when proposed into the base metal. They could also improve material characteristics under particular loading conditions.
Those incorporations are regularly selected in the traditional fabrication of metal matrix composites, but they have been practically studied in laser-endorsed additive manufacturing techniques. In the meantime, the complexity of attaining better wettability between the base metal and reinforcing fillers is also marked as a primary hitch [68]–[70]. Hence, the advancement of novel reinforcement components and infiltrant components with higher bondability and permeability with a base metal. This is precisely correct for the laser-endorsed additive manufacturing of metal matrix composites warrants vital research interest. There are various unfamiliar principles in the technique like vaporization and degradation of reinforcement filler, and compassionating the focus will highly support the mechanical and morphological characteristics of the additive manufactured-based metal composites.
Also, the size and geometry influence of the base and reinforcement fillers are infrequently investigated in laser-endorsed additive manufacturing of metal composites. In contrast, these factors are affirmed crucial to produce microstructure and porosity in traditional powder metallurgy technology [71]–[73].
In addition, because of the behavior of laser- endorsed additive manufacturing techniques, the as- built constituents have been dominated by challenging problems like lower surface quality, distortion of geometry, higher gradient tress, and higher porosity level. Post-modification is wisely predicted to alleviate these negative influences and enhance constituents' characteristics. The investigation on post-modifying additive manufacturing created general metal alloys is ample, and various techniques of hot isostatic pressing, mechanical rolling, ultrasonic peening, machining, and heat treatment have been pursued. Furthermore, the investigation on post-modifying additive manufacturing created metal-based composites has been underdeveloped.
The endorsement of post-modifications enhancing reinforcement/matrix interface, decreasing the porosity, and uniform microstructure of laser-endorsed additive manufacturing fabricated metal matrix composites should be marked. Indeed, from a schematic viewpoint,
a laser-endorsed additive manufactured technique has evident to be inexpensive, containing expensively raw particle production and costly post-processing technique. To efficiently decrease the price and comprehend the industrial utilization of the laser- endorsed manufacturing method, further research is necessary to reduce the price of raw particle production and post-processing technique.
Various issues should be affected to develop the utilization of metal matrix composites. Product and research advancement and business and design development abilities are essential to exceed these issues. For these causes, there is a necessary need to inscribe specific interests. The science of the metal matrix composites processing technique has to be appreciated thoroughly, particularly the parameters that influence the structural integrity, including the accumulation of the reinforcement fillers. Methods to enhance fracture toughness, damage tolerances, and laminates flexibility should be considered. The primary problem in the metal matrix composites is the secondary processing methods. Research investigation must be enhanced to connect the metal matrix composites with slight attempt; furthermore, exceptional tool advancements are essential for machining the metal matrix composites [74].
4 Sustainability
There is increasing interest in environmental effects in selecting sustainable components in the construction company. Universally, the primary problem of environmental pollution and resource depletion is the construction company: bridges and railways, Roads roads and superstructures [75]. Van Erpa and Rogers [76] recorded that about 40% of the primary constituents and energy created on Earth earth are absorbed from the construction industry that achieves millions of air, water pollutants, and greenhouse gases. Sustainability is a broad principle that influences environmental, social, and economic parameters [77].
Furthermore, a complex principle can be termed in a simple definition [78]. Sustainability can initially be recognized as a principle of renewable sources like fisheries or forests that consequently developed into broad spread phrases for environmental developments [79]. Thus, a massive ratio of patrons assumes which that sustainability holds human life at a particular
range in the current ecological environment and provides the upcoming genesis [80]. In the engineering sector, sustainability targets stakeholders' needs while absorbing fewer components and lower energy using the complete product life cycle. Presently, there are developing quantities of waste components that have been created at the end of the life cycle of railway architecture schemes. Thus, novel laminate materials with higher recycling must be broadly applied and invented [27].
5 Appraisal of Life Cycle Performance and Waste Management
Usually, there are two same principles to appraise recycling waste in the railway sector. Both directions empower an exceptional result. One approach is termed four Rs techniques that estimate the recoverability and recyclability rate to determine the end of life. Another method is the environmental life cycle assessment process that encloses a diversification of assessment techniques that can determine the life cycle in the perceptible method. This method is applied to calculate the environmental performance assigned with a component through its complete life cycle for both the partial and whole schemes that target the emission of components, recycling of resources, and energy between grave and cradle. Both technologies offer many advantages by modifying wastes into novel components. They both have excellent investigation importance for the construction of lower carbon and waste management.
5.1 Recycling and recovering technique
Recycling is the technique of processing or converting waste components into valuable products [25], [81].
Also, recovering developed energies from assigning old components or machines into different forms of energy [82]. Furthermore, recovering also gives the waste recovering technique, targeted under recovering components primarily in thermal energy [83]. Both recovering and recycling techniques target to enhance the lifetime and use-value of components while decreasing environmental effects from recycling waste components. The whole scheme of the method depends on attempts to recover energy from waste, re-use, reduce, and recycle waste. Even though, there are no
existing information sources for railway turnout, it also can be a protocol to estimate recovery and recycling rate from reasonable alterations. As observed in the literature survey from Vandermenlen et al. [84], trains' potential component recycling advent was applied to estimate the environment's performance.
Furthermore, many scientists [82], [85], [86]
observed the recovery and recycling rate of rolling assets using their lifespan. Currently, there are developing quantities of wastes that have been created at the end of life of railway materials. Hence, it is essential to measure recovery and recycling rate for railway turnout schemes.
5.2 Environmental life cycle assessment
The model of the life cycle of railway turnout can be termed from many stages, with maintenance, operations, manufacturing, planning, construction, management of end of life, and design in the field of the railway. This research appraises the environmental influences correlated with a general railway turnout scheme. Lee et al. [87] illustrate the dominant researchers who have established intensity on the determinations of emission of greenhouse gases between grave and cradle for railway infrastructures.
Furthermore, Kaewunruen and Lian [88] examined life cycle assessment for railway turnout depending on employing modeling of 6-dimensional building data. Essentially, carbon dioxide was the outstanding greenhouse gas that resulted in global warming [89].
To manifest the characteristics of environmental influences, these greenhouse gases are indicated as carbon dioxide, that which was termed from the design of experiments. In this investigation, carbon dioxide and energy consumption are borrowed as signifiers to determine the environmental effects quantifiably.
In the recent analysis, the formulation of the railway turnout is to offer resilience to railway schemes by permissive the connection of trains. The critical formulation group of the turnout scheme and its materials is to encourage which continuous stress range using the path bed can be attained using sources with unique interest to turnout conveyor components [27].
6 Conclusions
Metal matrix composites can be intended according
to the requirement of various railway systems with the combination of adequate constituents and present extra-ordinary characteristics which are rigid to present by monolithic components. Metal matrix composites incorporated with different ceramic fillers showed enhanced tribological and mechanical features than pure metallic material and were more enhanced with incremented reinforcement concentration. The lightweight, ductile aluminum base metal is the most favored matrix component. Hybrid laminates consumed better characteristics than the pure base metal and mono laminates. The manufacturing technique is essential in advancing composite components with advanced elements. Among all the metal matrix composite fabrication methods employed, the stir casting technique is the least expensive, effortless, and can be applied for the vast production of metal matrix composites. The extrusion of stir-casted metal matrix composites can increment the dispersion of reinforcement and interfacial bonding. The preheating of support of fillers before the distribution and utilization of flux can resolve the wettability problems of reinforcement fillers with the melted metal. Accumulation appears as fillers slide on the melt base metal because of the density difference that may prevent the two-step incorporation of reinforcement fillers. The incremented surface region of nano-scale reinforcement fillers creates filler dispersion, and wettability delivers more asserting. Ultrasonic modification helps distribute fillers with bonding to a metal matrix. The compo casting technique conveys excellent wettability in matrix and reinforcement, better particle dispersion, and disrupts chemical reactions between reinforcements and metal matrix. Metal matrix composites manufactured from squeeze casting achieved higher characteristics than the stir casting process. Even squeeze single-cast laminates possess enhanced characteristics over stir casting hybrid laminates. Fast solidification in the method of thermal spray prohibits aggregation. The infiltration technique can distribute better wettability and restrict the surplus interfacial reactions.
The railway system has attained one of the most effective modes of transportations. Furthermore, a considerable quantity of waste has been created because of the essential utilization of components with more decisive environmental influence generally left in landfill regions. It is observed that the utilization of composites will decrease the frequency of the railway
industry. Nonetheless, employing an extensive design scheme can assure the safe performance of future railway schemes. It adheres that higher recovery and lower carbon composite components can be sustainable.
It is essential to note which that this investigation has also considered in detail the maintenance region.
In this context, a considerable quantity of exercises could affect the outcome in carbon emission during the reconstruction region. Also, the consumption of energy for machinery applied is complex to be calculatde.
As an issue, the information source involved in this investigation may be dissimilar from different projects based on the detailed methods.
Nevertheless, this investigation can still be applied as a note for future turnout schemes. Hence, with these restrictions, a more extensive examination is needed for a prospective study targeting the treatment of wastes and price examination. Also, because insufficient information is abundant for examining four Rs of railway turnout constituents, further investigation is required to offer practical information support.
Future analysis will commence on more studies in the recycling technique of composite components and flexible maintenance administrations, which would permit more carbon-effective solutions for the utilization of hybrid matters in railway infrastructure schemes.
References
[1] H. R. Hawkins, B. Singh, G. Majeau-Bettez, and A. H. Stromman, “Comparative environmental life cycle assessment of conventional and electric vehicles,” Journal of Industrial Ecology, vol. 13, pp. 53–64, Feb. 2013.
[2] R. L. Milford and J. M. Allwood, “Assessing the CO2 impact of current and future rail track in the UK,” Transportation Research Part D: Transport and Environment, vol. 15, pp. 61–72, Mar. 2010.
[3] M. Meinhausen, L. Jeffery, J. Guetschow, Y. R.
du Pont, J. Rogelj, M. Schaeffer, N. Höhne, M.
den Elzen, S. Oberthür, and N. Meinshausen,
“National post-2020 greenhouse gas targets and diversity-aware leadership,” Nature Climate Change, vol. 5, pp. 1098–1166, Oct. 2015.
[4] S. Yeh, G. S. Mishra, L. Fulton, P. Kyle, D. L.
McCollum, J. Miller, P. Cazzola, and J. Teter,
“Detailed assessment of global transport-energy
models' structures and projections,” Transportation Research Part D: Transport and Environment, vol. 55, pp. 294–309, Aug. 2017.
[5] A. Damm, J. Köberl, F. Prettenthaler, N. Rogler, and C. Töglhofer, “Impacts of +2 °C global warming on electricity demand in Europe,”
Climate Services, vol. 7, pp. 12–30, Aug. 2017.
[6] K. Sakdirat and L. Qiang, “Digital twin aided sustainability-based lifecycle management for railway turnout systems,” Journal of Cleaner Production, vol. 228, pp. 1537–1551, Aug. 2019.
[7] W. Sihan, M. Reza, B. Janet, and B. R. George,
“Tensile strength and water absorption behavior of recycled jute-epoxy composites,” Journal of Renewable Materials, vol. 4, pp. 279–288, Nov.
2013.
[8] A. Manalo, T. Aravinthan, W. Karunasena, and A. Ticoalu, “A review of alternative materials for replacing existing timber sleepers,” Composite Structures, vol. 92, pp. 603–611, Feb 2010.
[9] W. Ferdous, A. Manalo, G. V. Erp, T. Aravinthan, S. Kaewunruen, and A. Remennikov, “Composite railway sleepers – Recent developments, challenges and future prospects,” Composite Structures, vol. 134, pp. 158–168, Dec. 2015.
[10] R. Ford, “Transport mass: Weight saving and structural integrity of rail vehicles,” Institution of Mechanical Engineers, Derby, UK, 2007.
[11] J. P. Loubinoux and L. Lochman, “Moving towards sustainable mobility: A strategy for 2030 and beyond for the European railway sector,”
Paris, France: International Union of Railways (UIC); 2012.
[12] J. J. Carruthers, M. Calomfirescu, and P. Ghys, J.
Prockat, “The application of a systematic approach to material selection for the lightweighting of metro vehicles,” Proceedings of the Institution of Mechanical Engineers Part F, vol. 223, pp. 427–
437, Jun. 2009.
[13] P. J. Mistry, M. S. Johnson, S. Li, S. Bruni, and A. Bernasconi, “Parametric sizing study for the design of a lightweight composite railway axle,”
Composite Structures, vol. 267, Jul. 2021, Art.
no. 113851.
[14] I. Sinclair and P. J. Gregson, “Structural performance of discontinuous metal matrix composites,” Materials Science and Technology, vol. 13, pp. 709–726, Jul. 2013.
[15] D. L. McDanels, “Analysis of stress-strain, fracture, and ductility behavior of aluminum matrix composites containing discontinuous silicon carbide reinforcement,” Metallic Transactions A, vol. 16, pp. 1105–1115, Jun. 1985.
[16] J. E. Allison and G. S. Cole, “Metal-matrix composites in the automotive industry:
Opportunities and challenges,” Journal of Materials, vol. 45, pp. 19–24, Jan. 1993.
[17] M. K. Surappa, “Aluminium matrix composites:
Challenges and opportunities,” Sadhana, vol. 28, pp. 319–334, Feb. 2003.
[18] K. S. R. Kumar, C. Ratnam, and B. Nagababu,
“Fabrication and mechanical behavior of Al 2024–B4C MMCs and Al 2024– B4C-Gr hybrid MMCs through powder metallurgy technique,”
Materials Today: Proceedings, vol. 18, pp. 219–
229, Oct. 2019.
[19] S. J. Harris, “AGARD lectures series no. 174,”
in New Light Alloys. Neuilly sur Seine, France:
North Atlantic Treaty Organization, 1990.
[20] B. C. Kandpal, J. Kumar, and H. Singh,
“Manufacturing and technological challenges in stir casting of metal matrix composites - A review,” Materials Today: Proceedings, vol. 5, pp. 5–10, Feb. 2018.
[21] Y. Waku and T. Nagasawa, “Future trends and recent developments of fabrication technology for advanced metal matrix composites,” Materials and Manufuring Process, vol. 9, pp. 937–963, Apr. 2007.
[22] M. Rosso, “Ceramic and metal matrix composites:
Routes and properties,” Journal of Materials Processing Technology, vol. 175, pp. 364–375, Jun. 2006.
[23] A. Manna, H. S. Bains, and P. B. Mahapatra,
“Experimental study on fabrication of Al—
Al2O3/Grp metal matrix composites,” Journal of Composite Materials, vol. 45, pp. 2003–2010, Jan. 2011.
[24] E. Ghasali, A. Pakseresht, F. Safari-Kooshali, M. Agheli, and T. Ebadzadeh, “Investigation on microstructure and mechanical behavior of Al–ZrB2 composite prepared by microwave and spark plasma sintering,” Materials Science and Engineering A, vol. 627, pp. 27–30, Feb. 2015.
[25] J. Bowyer, S. Bratkovich, K. Fernholz, M. Frank, H. Groot, J. Howe, and E. Pepke, Understanding
Steel Recovery and Recycling Rates and Limitations to Recycling. MN: Dovetail Partners, 2015, pp. 1–12.
[26] R. Silva and S. Kaewunruen, “Recycling of rolling stocks,” Environment, vol. 4, p. 39, May.
2017.
[27] S. Kaewunruen and P. Liao, “Sustainability and recyclability of composite materials for railway turnout systems,” Journal of Cleaner Production, vol. 285, Feb. 2021, Art. no. 124890.
[28] B. Indaratna, M. A. Shahin, and W. Salim, “Use of geosynthetics for stabilizing recycled ballast in railway track substructures,” Engineering, pp. 1–15, 2005, Art. no. 13735.
[29] A. Bracciali and G. Megna, “Inside frame bogies
& air wheelset a winning marriage,” presented at the 10th International Conference on Railway Bogies and Running Gears, Budapest, Hungary, Sep. 12–15, 2016.
[30] Railway Applications. Wheelsets and Bogies, Part 1: Design Method for Axles with External Journals; CSN EN 13103-1:2017, 2017.
[31] U. Zerbst, S. Beretta, G. Köhler, A. Lawton, M. Vormwald, H. Beier, C. Klinger, I. Cern, J.
Rudlin, T. Heckel, and D. Klingbell, “Safe life and damage tolerance aspects of railway axles–
A review,” Engineering Fracture Mechanics, vol. 98, pp. 214–271, Jan. 2013.
[32] Railway applications. Rolling stock equipment.
Shock and Vibration Tests, BS EN 61373:2010, 2010.
[33] Railway applications. Environmental Conditions for Equipment, Part 1: Rolling Stock and On- Board Equipment, BS EN 50125-1:2014, 2014.
[34] Railway Applications. Fire Protection on Railway Vehicles, Requirements for Fire Behaviour of Materials and Components, BS EN 45545- 2:2013+A1:2015, 2013.
[35] S. Cervello and D. Sala, “LURSAK: Development of innovative anti impact coating return from experience,” presented at the 17th International Wheelset Congress, Kiev, Ukraine, Sep. 22–27, 2013.
[36] P. J. Mistry, M. S. Johnson, C. A. McRobie, and I. A.
Jones, “Design of a lightweight multifunctional composite railway axle utilising coaxial skins,”
Journal of Composite Science, vol. 5, p. 77, Mar. 2021.
[37] M. K. Akbari, S. Rajabi, K. Shirvanimoghaddam, and H. R. Baharvandi, “Wear and friction behavior of nanosized TiB2 and TiO2 particle-reinforced casting A356 aluminum nanocomposites: A comparative study focusing on particle capture in matrix,” Journal of Composite Materials, vol. 49, pp. 3665–3681, Jan. 2015.
[38] Y. Dou, Y. Liu, Y. Liu, Z. Xiong, and Q. Xia,
“Friction and wear behaviors of B4C/6061Al composite,” Materials and Design, vol. 60, pp. 669–677, Aug. 2014.
[39] V. Auradi, G. Rajesh, and S. Kori, “Preparation, characterization and evaluation of mechanical properties of 6061Al-reinforced B4C particulate composites via two-stage melt stirring,”
Materials and Manufacturing Processes, vol. 29, pp. 194–200, Sep. 2014.
[40] S. Das, M. Chandrasekaran, S. Samanta, P.
Karyoganam, and J. P. Davim, “Fabrication and tribological study of AA6061 hybrid metal matrix composites reinforced with SiC/B4C nanoparticles,” Industrial Lubrication and Tribology, vol. 71, pp. 83–93, Oct. 2019.
[41] K. Padmavathi and R. Ramakrishnan, “Tribological behaviour of aluminium hybrid metal matrix composite,” Procedia Engineering, vol. 97, pp. 660–667, Dec. 2014.
[42] Y. Zhou, Y. N. Zan, S. J. Zhang, Q. Z. Wang, B.
L. Xiao, X. L. Ma, and Z. Y. Ma, “Distribution of the microalloying element Cu in B4C-reinforced 6061Al composites,” Journal of Alloys and Compounds, vol. 728, pp. 112–117, Dec. 2017.
[43] P. Balamurugan and M. Uthayakumar, “Influence of process parameters on Cu–Fly ash composite by powder metallurgy technique,” Materials and Manufacturing Processes, vol. 30, pp. 313–319, Jan. 2015.
[44] Y. Zan, Q. Zhang, Y. T. Zhou, Q. Z. Wang, B. L.
Xiao, and Z. Y. Ma, “Enhancing high-temperature strength of B4C–6061Al neutron absorber material by in-situ Mg (Al) B2,” Journal of Nuclear Materials, vol. 526, p. 151788, Dec. 2019.
[45] M. Akbarpour, H. M. Mirabad, and S. Alipour,
“Microstructural and mechanical characteristics of hybrid SiC/Cu composites with nano-and micro-sized SiC particles,” Ceramic International, vol. 45, pp. 3276–3283, Feb. 2019.
[46] N. Al-Aqeeli, K. Mohammad, T. Laoui, and N.
Saheb, “The effect of variable binder content and sintering temperature on the mechanical properties of WC–Co–VC/Cr3C2 nanocomposites,”
Materials and Manufacturing Processes, vol. 30, pp. 327–334, Dec. 2014.
[47] J. D. R. Selvam, I. Dinaharan, S. V. Philip, and P. M. Mashinini, “Microstructure and mechanical characterization of in situ synthesized AA6061/(TiB2 + Al2O3) hybrid aluminum matrix composites,” Journal of Alloys and Compounds, vol. 740, pp. 529–535, Apr. 2018.
[48] J. D. R. Selvam, I. Dinaharan, R. S. Rai, and P. M.
Mashinini, “Role of zirconium diboride particles on microstructure and wear behaviour of AA7075 in situ aluminium matrix composites at elevated temperature,” Tribological Materials and Surface Interfaces, vol. 13, no. 4, pp. 1–9, Sep. 2019.
[49] D. K. Sharma, M. Sharma, and G. Upadhyay,
“Boron carbide (B4C) reinforced aluminum matrix composites (AMCs),” International Journal of Innovative Technology and Exploring Engineering, vol. 9, pp. 2194–2203, Nov. 2019.
[50] A. Simchi and H. Pohl, “Direct laser sintering of irongraphite powder mixture,” Materials Science and Engineering A, vol. 383, pp. 191–200, Oct.
2004.
[51] Q. Jia and D. Gu, “Selective laser melting additive manufacturing of Inconel 718 superalloy parts: Densification, microstructure and properties,” Journal of Alloys and Compounds, vol. 585, pp. 713–721, Feb. 2014.
[52] J. M. Wilson and Y. C. Shin, “Microstructure and wear properties of laser-deposited functionally graded Inconel 690 reinforced with TiC,” Surface Coating and Technology, vol. 207, pp. 517–522, Aug. 2012.
[53] C. Cui, Z. Guo, H. Wang, and J. Hu, “In situ TiC particles reinforced grey cast iron composite fabricated by laser cladding of Ni-Ti-C system,”
Journal of Materials Processing Technology, vol. 183, pp. 380–385, Mar. 2007.
[54] B. Zheng, T. Topping, J. E. Smugeresky, Y. Zhou, A. Biswas, D. Baker, and E. J. Lavernia, “The influence of Ni-coated TiC on laser-deposited IN625 metal matrix composites,” Metallic Materials Transactions A, vol. 41, pp. 568–573, Jan. 2010.
[55] Y. Wang and J. Shi, “Effect of post heat treatment
on the microstructure and tensile properties of nano TiC particulate reinforced Inconel 718 by selective laser melting,” Journal of Manufacturing Science and Engineering, vol. 142, Mar. 2020, Art. no. 051004.
[56] T. Rong, D. Gu, Q. Shi, S. Cao, and M. Xia,
“Effects of tailored gradient interface on wear properties of WC/Inconel 718 composites using selective laser melting,” Surface Coating Technology, vol. 307, pp. 418–427, Dec. 2016.
[57] D. Lin, C. R. Liu, G. J. Cheng, Q. Nian, R. Xu, M.
Saei, F. Chen, C. Chen, M. Zhang, H. Guo, and J.
Xu, “Laser sintered single layer graphene oxide reinforced titanium matrix nanocomposites,”
Composites Part B: Engineering, vol. 93, pp. 352–359, May. 2016.
[58] Y. Wang, J. Shi, S. Lu, and Y. Wang, “Selective laser melting of graphene-reinforced Inconel 718 superalloy: Evaluation of microstructure and tensile performance,” Journal of Manufacturing Science and Engineering, vol. 139, Apr. 2017, Art. no. 041005,
[59] W. Xiao, S. Lu, Y. Wang, and S. H. I. Jing,
“Mechanical and tribological behaviors of graphene/Inconel 718 composites,” Transactions of Nonferrous Metal Society of China, vol. 28, pp. 1958–1969, Oct. 2018.
[60] Y. Wang and J. Shi, “Microstructure and tensile performance of graphene-reinforced Inconel 718 alloy via selective laser melting and post-treatments,” Journal of Micro and Nano Manufacturing, vol. 8, Mar. 2020, Art. no. 011005.
[61] H. Attar, S. Ehtemam-Haghighi, D. Kent, and M. S. Dargusch, “Recent developments and opportunities in additive manufacturing of titanium-based matrix composites: A review,”
International Journal of Machine Tools and Manufacturing, vol. 133, pp. 85–102, Oct. 2018.
[62] D. Gu, Z. Wang, and Y. Shen, “In-situ TiC particle reinforced Ti-Al matrix composites: Powder preparation by mechanical alloying and selective laser melting behavior,” Applied Surface Science, vol. 255, pp. 9230–9240, Aug. 2009.
[63] Y. Zhang, J. Sun, and R. Vilar, “Characterization of (TiB + TiC)/TC4 in situ titanium matrix composites prepared by laser direct deposition,”
Journal of Materials Processing Technology, vol. 211, pp. 597–601, Apr. 2011.
[64] D. Gu, Y. C. Hagedorn, W. Meiners, K. Wissenbach, and R. Poprawe, “Selective laser melting of in situ TiC/Ti5Si3 composites with novel reinforcement architecture and elevated performance,” Surface Coating Technology, vol. 205, pp. 3285–3292, Feb. 2011.
[65] D. E. Cooper, N. Blundell, S. Maggs, and G. J.
Gibbons, “Additive layer manufacture of Inconel 625 metal matrix composites, reinforcement material evaluation,” Journal of Materials Processing Technology, vol. 213, pp. 2191–2200, Dec. 2013.
[66] C. Hong, D. Gu, and D. Dai, “High-temperature oxidation performance and its mechanism of TiC/
Inconel 625 composites prepared by laser metal deposition additive manufacturing,” Journal of Laser Applications, vol. 27, Dec. 2014, Art. no.
S17005.
[67] G. Bi, C. N. Sun, M. L. Nai, and J. Wei, “Micro- structure and mechanical properties of nano-TiC reinforced Inconel 625 deposited using LAAM,”
Physics Proceedings, vol. 41, pp. 828–834, Dec.
2013.
[68] D. Gu, Y. Shen, and Z. Lu, “Microstructural characteristics and formation mechanism of direct laser-sintered Cu-based alloys reinforced with Ni particles,” Materials and Designs, vol. 30, pp. 2099–2107, Jun. 2009.
[69] L. Lu, J. Y. H. Fuh, Z. D. Chen, C. C. Leong, and Y. S. Wong, “In situ formation of TiC composite using selective laser melting,” Materials Research Bulletin, vol. 35, pp. 1555–1561, Jul. 2000.
[70] C. C. Leong, L. Lu, J. Y. H. Fuh, and Y. S. Wong,
“In-situ formation of copper matrix composites by laser sintering,” Materials Science and Engineering A, vol. 338, pp. 81–88, Dec. 2002.
[71] M. Rahimian, N. Ehsani, N. Parvin, H. Baharvandi, and H. Reza, “The effect of particle size, sintering temperature and sintering time on the properties of Al-Al2O3 composites, made by powder metallurgy,” Journal of Materials Processing Technology, vol. 209, pp. 5387–5393, Jul. 2009.
[72] Y. Flom and R. J. Arsenault, “Effect of particle size on fracture toughness of SiC/Al composite material,” Acta Metallurgica, vol. 37, pp. 2413–
2423, Sep. 1989.
[73] S. M. Uddin, T. Mahmud, and C. Wolf, “Effect of size and shape of metal particles to improve hardness
and electrical properties of carbon nanotube reinforced copper and copper alloy composites,”
Composites Science and Technology, vol. 70, pp. 2253–2257, Dec. 2010.
[74] P. V. Reddy, G. S. Kumar, D. M. Krishnudu, and H. R. Rao, “Mechanical and wear performances of aluminium-based metal matrix composites:
A review,” Journal of Bio and Tribo Corrosion, vol. 6, p. 83, Jun. 2020.
[75] G. V. Erp and M. Mckay, “Recent Australian developments in fiber composite railway sleepers,”
Electronic Journal of Structural Engineering, vol. 13, pp. 62–66, Jan. 2013.
[76] G. V. Erp and D. Rogers, “A highly sustainable fiber composite building panel,” in Proceedings of the International Workshop on Fiber Composites in Civil Infrastructure-Past, Present, and Future, 2008, pp. 1–2.
[77] K. Hydes and L. Creech, “Reducing mechanical equipment cost: The economics of green design,”
Building Research and Information, vol. 28, pp. 403–407, 2000.
[78] L. Zhou and D. J. Lowe, “Economic challenges of sustainable construction,” in Proceedings of the RICS Construction and Building Research Conference, 2003, pp. 113–126.
[79] S. Lele', “The concept of sustainability,” in Natural Resources Modelling and Analysis:
Proceedings of an Interdisciplinary Conference Held at St, 1993, pp. 46–48.
[80] S. M. Lele, “Sustainable development: A critical review,” World Development, vol. 19, pp. 607–
621, Jun. 1991.
[81] M. Dauguet, O. Mantaux, N. Perry, and Y. F. Zhao,
“Recycling of CFRP for high value applications:
Effect of sizing removal and environmental analysis of the super critical fluid solvolysis,”
Procedia CIRP, vol. 29, pp. 734–739, 2015.
[82] S. Kaewunruen, P. Rungskunroch, and D. V.
Jennings, “A through-life evaluation of end-of- life rolling stocks considering asset recycling, energy recovering, and financial benefit,” Journal of Cleaner Production, vol. 212, 1008–1024, Mar. 2019.
[83] L. Serrano, T. Lewandrowski, P. Liu, and S.
Kaewunruen, “Environmental risks and uncertainty with respect to the utilization of recycled rolling stocks,” Environment, vol. 4, p. 62, Sep. 2017.
[84] B. Vandermeulen, W. Dewulf, J. Duflou, A.
Ander, and T. Zimmermann, “The use of performance indicators for environmental assessment within the railway business: The RAVEL workbench prototype, a web-based tool,” Journal of Cleaner Production, vol. 11, pp. 779–785, Nov. 2003.
[85] S. Kaewunruen, J. Sresakoolchai, and S. Yu,
“Global warming potentials due to railway tunnel construction and maintenance,” Applied Science, vol. 10, Sep. 2020, Art. no. 6459.
[86] S. Krezo, O. Mirza, S. Kaewunruen, and J. M.
Sussman, “Evaluation of CO2 emissions from railway resurfacing maintenance activities,”
Transportation Research Part D, vol. 65, pp. 458–
465, 2018.
[87] C. K. Lee, J. Y. Lee, Y. H. Choi, and K. M. Lee,
“Application of the integrated ecodesign method using the GHG emission as a single indicator and its GHG recyclability,” Journal of Cleaner Production, vol. 112, pp. 1692–1699, Jan. 2016.
[88] S. Kaewunruen and Q. Lian, “Digital twin aided sustainability-based lifecycle management for railway turnout systems,” Journal of Cleaner Production, vol. 228, pp. 1537–1551, Aug. 2019.
[89] S. Rawlinson and D. Weight, “Sustainability:
Embodied carbon,” Building Magazine, vol. 12, pp. 88–91, 2007.
