It is hereby declared that the work in this thesis, entitled Dry Sliding Wear Response of Fly Ash Filled Poly-Ether-Ether-Ketone Composites by Alok Kumar Sahoo, has been carried out under my supervision and is in partial fulfillment of the requirements for the degree of Bachelor of Technology in Mechanical Engineering during a session at the Department of Mechanical Engineering, National Institute of Technology, Rourkela. Fly ash is generated in large quantities from furnaces in coal-based thermal power plants during power generation worldwide. The fly ash particles with an average size of 100 microns are reinforced in PEEK resin to prepare particle-filled composites of three different compositions (0, 7.5 and 15 wt% fly ash).
The effect of fly ash content on the wear rate of PEEK composites under different test conditions is studied. This technique helps save time and resources for a large number of experimental tests and predicts the wear response of fly ash-filled PEEK composites within and outside the experimental domain. This work involves the fabrication of a polymer (PEEK) composite reinforced with fly ash particles and its subsequent response to dry sliding wear.
The fly ash-PEEK composite is a two-phase composite where PEEK is the matrix and fly ash particles constitute the dispersed phase.
Fly ash
Wear
LITERATURE REVIEW
- Fabrication of composite
- Sliding Wear Test
- Scanning Electron Microscopy
- Experimental Design
It has been observed that by incorporating solid filler particles into polymer-based composites; synergistic effects can be achieved in the form of higher modulus and reduced material cost (Pukanszky, 1995; Acosta et.al, 1986; Gregory et.al, 2003). The incorporation of such particulate fillers into polymers for commercial applications is primarily aimed at reducing cost and improving stiffness (Rothon, 1997; Rothon 1999). However, the study of the effect of such filler addition is necessary to ensure that the mechanical properties of the composites are not adversely affected by such an addition. The wear process in composites has been observed to depend significantly on the characteristics of the filler materials (Khedkar Jaydeep et. al, 2002).
Wear is said to occur in a mutual environment as it is found that change in load, sliding distance, filler content and speed or a combination of any of the parameters changes the rate of wear (Suresha S. et.al, 2010). shows that the plastic-elastic damage of the composite depends on the particle size. The analysis of the effect of the characteristic parameters on the wear behavior was successfully carried out using the Taguchi experimental technique design strategy (Patnaik et.al, 2009; Taguchi parameter design can optimize the performance characteristics by setting the design parameters and reduce the sensitivity of the source of variation (Basavarajappa S.
The experimental results are analyzed using the analysis of means and variance of the influence of factors (Taguchi G. 1993). The specific wear rate is defined as the sample's volume loss per sliding unit per unit subjected to normal load. The worn surfaces of the samples are examined directly using a scanning electron microscope JEOL JSM-6480LV.
In order to increase the conductivity of the samples, a thin film of platinum is vacuum-evaporated on them before the photomicrographs. The most important step in designing an experiment is the selection of control factors. The S/N ratio for the minimum erosion rate falls under the smaller-is-better characteristic, which can be calculated as a logarithmic transformation of the loss function as shown below.
RESULTS & DISCUSSION
- Dry Sliding Wear Test Results
- Factor Settings for Minimum Specific Wear Rate of Fly Ash – PEEK Composites
- Surface Morphology
- Comparison of TiO 2 filled composite with fly ash filled composite
- Analysis using ANN
The specific wear rates obtained for all 9 test runs, together with the corresponding S/N ratio, are shown in the table below. The S/N ratio response analysis shows that among all factors, sliding speed is the most important factor, followed by filler content and normal load, while sliding distance has the least or almost no significance on the wear rate of the particle-filled composites in this study . . The analysis of the results leads to the conclusion that the factor combination of A1, B3 and C3 produces the minimum specific wear rate.
The S/N ratio response is given in Table 4, from which again it can be concluded that among all the factors, sliding speed is the most significant factor followed by filler content and normal load while sliding distance has the least importance or almost not at all. on particle composition wear. In this study, an attempt has been made to derive a predictive correlation in terms of important control factors for determining the specific wear rate of these fly ash filled PEEK composites. The worn surface morphology of the PEEK composite with 7.5 wt% fly ash is illustrated in Figure 5 .
It can be seen that there is a plastic flow of the matrix material in the sliding direction, which is indicated by the arrows (Figure 5a). As a result, the fly ash particles, which are brittle in nature and have sharp edges, easily tear the matrix and are gradually aligned along the sliding direction, as seen in Figure 5(b). It has been found that, under the same experimental conditions, the titanium dioxide-filled composite shows better wear resistance than the fly ash-filled composite.
It is seen that although titanium oxide exhibits better wear behavior as a filler material, the wear rates obtained for fly ash are comparable to titanium dioxide. A software package NEURALNET for neural computing using back-propagation algorithm is used as prediction tool for specific wear rate of the composite samples under different test conditions. Keeping normal load constant at 10N, the simulated specific wear rates indicating the effects of varying filler content (fly ash) and sliding velocities are shown in Figure 8.
It is interesting to note that while the specific wear rate decreases almost exponentially with increasing fly ash content in the composite, indicating an improvement in the wear resistance of the composite, it increases with increasing sliding speed. The presence of fly ash particles appears to have helped limit mass loss from the composite surface due to sliding wear.
CONCLUSION
The dry skid wear characteristics of these composites can be experimented with following a design-experiment approach. This study reveals that fly ash possesses good filler characteristics as it improves the sliding wear resistance of the composite. The artificial neural network (ANN) technique has been successfully applied in this investigation to predict and simulate the wear response of ingredients under different test conditions in and out of the experimental field.
Duroplastic polymers such as epoxy or polyester can be used as a matrix material and the potential of industrial wastes other than fly ash can be explored.
REFEERNCES
Effect of Addition of Sepiolite on the Mechanical Properties of Glass Fiber Reinforced Polypropylene Angew Makromol Chem pp A Study of Friction and Wear Behavior of PTFE Filled with Aluminum Oxide Nanoparticles Wear p Modeling and Prediction of Erosion Response of Glass Reinforced Polyester Flyash CompositesJournal of Reinforced Plastics and Composites p .
Study on Friction and Wear Behavior of Polyphenylene Sulfide Composites Reinforced with Short Carbon Fibers and Sub-Micro TiO2 Particles, Composites, Science and Technology pp. Wear Characteristics of Hybrid Aluminum Matrix Composites Reinforced with Graphite and Silicon Carbide Particles, Composites Study on Technology pp. Friction and Sliding Wear Behavior of woven S-glass fiber reinforced vinyl ester composite prepared with different comonomers, J.
Influence of sliding speed on the dry sliding wear behavior and subsurface deformation of hybrid metal matrix composite, Wear, Vol. Evaluation and prediction of the wear response of pine dust filled epoxy composites using neural computations, Computational Material Science pp. Tribo performance analysis of red mud filled glass-epoxy composites using Taguchi experimental design, Materials and Design, (2009).
PUBLICATIONS
Dry Sliding Wear Response of LD Slag Filled Poly-ether-ether-ketone Composites
The most important stage in the design of the experiment lies in the selection of control factors. Four parameters, ie, sliding speed, LDS content, normal load, and sliding distance each at three levels, were considered in this study in accordance with the L9 orthogonal array design (34). The minimum erosion rate under the smallest-is-better characteristic, which can be calculated as the logarithmic transformation of the loss function as shown below. The S/N ratio response is given in Table 3, from which again it can be concluded that among all the factors, sliding speed is the most significant factor followed by filler content and normal load while sliding distance has the least importance or almost not at all. on particle composition wear.
The morphology of the worn surface of the PEEK composite with 7.5 wt% LDS is shown in Figure 2. It can be seen that there is plastic flow of the matrix material in the sliding direction, which is indicated by the arrows (Figure 2a). Due to their size, shape, brittleness and high hardness, these particles affect the wear behavior of composites.
Based on the minimum error criterion, one structure is selected for training input-output data. It is interesting to note that while the specific wear rate decreases almost exponentially with the increase in the LDS content of the composite, indicating an improvement in the wear resistance of the composite, it increases with the increase in the sliding speed. The presence of LDS particles seems to have helped to limit the mass loss from the composite surface due to sliding wear.
This study reveals that LDS possesses good filler characteristics as it improves the sliding wear resistance of the composite. The artificial neural network (ANN) technique is successfully applied in this investigation to predict and simulate the wear response of ingredients under different test conditions within and beyond the experimental domain. Analysis of dry sliding wear behavior of red clay filled polyester composites using the Taguchi method, Journal of Reinforced Plastics and Composites doi Artificial Neural Networks Applied to Polymeric Composites: A Review.
