This special edition of the reprinted book provides concise reports on the current state of the art. Given the vast scientific and technological importance of this timely topic, this special issue on "Design of Materials and Processes for Lightweight Structures" has aimed to collect concise reports on the current state of the art.
Concluding Remarks
The aim of the study was to analyze the effects of various creep aging parameters on the creep behavior, mechanical properties and fatigue fracture behavior of a widely used Al-Cu-Mg alloy in the aerospace industry to advance the development of creep aging treatments of this class of aluminum alloys. Effect of process parameters on fatigue and fracture behavior of Al-Cu-Mg alloy after creep aging. Metals2018,8, 298.
Global and High-Resolution Damage Quantification in Dual-Phase Steel Bending Samples with Varying
- Introduction
- Materials and Methods
- Results
- Discussion
- Conclusions
For the validation of the identical tension at the outer fiber, optical measurements and hardness measurements are used. Therefore, it is assumed that the void area fractions for the undeformed state of the sheet metal do not exist.
A Mathematical Model of Deformation under High Pressure Torsion Extrusion
The Model
The sample material is assumed to be rigid-plastic and unhardened. Torques associated with frictional forces at the end faces of the specimen are neglected.
Results and Discussion
Figure 4 illustrates the accumulation of stress that progresses as the specimen moves through the holding elements. However, the magnitude of the equivalent strain in this portion of the specimen is somewhat reduced.
Conclusions
The results led to the selection of the process parameters and the production of some prototypes that were finally characterized. These analyzes demonstrate the feasibility of manufacturing hollow components by HPDC using ceramic cores.
Results and Discussion 1. FEA Results
Cross-sections of the hollowed-out component in the as-cast state were obtained for microstructural characterization. The results show a slight improvement of the new geometry behavior (cf. the arrows in Figure 11) compared to the traditional one. 50] was found in the samples "c-1110◦C", i.e. in the material selected for the manufacture of the hollowed aluminum component.
Figure 13 shows one of the cross-sections of the hollow component in the as-cast state, observed with an optical microscope.
Multilayered-Sheet Hot Stamping and Application in Electric-Power-Fitting Products
Features of the New Product and U-Shaped Tool
The traditional component carries a load of 240 kN with a nominal weight of about 7 kg [1]. a) (b) Figure 2. Structure of (a) the traditional fork and (b) the new fork. Considering the plastic stress behavior of the component structure, the mechanical property analysis used an explicit dynamic method [17-19]. Zhou designed a multilayer skin component and established a numerical model to predict the mechanical properties of the components.
The dimensions and (b) the finite element (FE) model of the new type of gaff.
Multilayered-Sheet Heat Transfer Experiment 1. Experiment Procedure
The temperature curves of two-layer plates at different contact pressures are shown in Figure 8. The technical curves of stress versus deformation of two-layer plates are shown in Figure 16. The technical curves of stress versus deformation of three-layer plates are shown in Figure 17.
The design stress versus strain curves for the four-ply sheets are shown in Figure 18.
New Product and Its Performance Tests
Compared to that of the traditional component, the weight of the new component was reduced by 60%. Analysis of the reasons behind the break of the horizontal line clamp of the 220 kV tube busbar. Effect of martensitic transformation on stamping strength and cycle time of hot stamping parts. Metals2018,8, 385.
A comparative study of microstructure and mechanical property prediction for a hot-stamped B-pillar stiffener.Int.
Modification of Microstructure and Texture in Highly Non-Flammable Mg-Al-Zn-Y-Ca Alloy Sheets by
Summary
After rolling the sheet at 500◦C, the basal pole split texture was developed in the RD, while the influence of the degree of deformation per rolling step on the microstructure and texture became negligible. The effect of calcium on the texture, microstructure and mechanical properties of extruded Mg-Mn-Ca alloys. Mater. Room temperature ductility of a magnesium AZ31 alloy: investigating the role of texture on the deformation mechanisms. Mater.
Effect of rare earth additions on microstructure and texture development of magnesium alloy sheets.Scr.
Effect of Surface Roughness on the Bonding Strength and Spring-Back of a CFRP/CR980 Hybrid Composite
Experiments
As the surface roughness of the CR980 increased, it was found that the bond strength of the CFRP/CR980 hybrid composite also increased. Figure 11 shows the thickness of the CFRP/CR980 hybrid composite performed by V-bending at different positions. Figure 13 shows the rebound angle of the CFRP/CR980 hybrid composite with different surface roughness performed by a V-bend test under 2 MPa of the pressure.
In this study, the bond strength and spring support of the CFRP/CR980: hybrid composite were investigated.
Connected Process Design for Hot Working of a Creep-Resistant Mg–4Al–2Ba–2Ca Alloy (ABaX422)
Experimental Procedure
The extraction process was designed based on the results from the processing map developed for the cast link in step 1, as discussed in the following sections. Microstructures obtained in extruded ABaX422 alloy specimens pressed under maximum efficiency conditions in four different areas of the processing map. The apparent activation parameters and the Circuit are evaluated with important data for different areas of the processing map for the extruded ABaX422 alloy.
The area of the flow instability regime shown in the cast alloy processing map is reduced by the extrusion step, and this increases the processability window.
Assessment of Metal Flow Balance in Multi-Output Porthole Hot Extrusion of AA6060 Thin-Walled Profile
Design Scheme of Multi-Output Porthole Extrusion Die 1. General Description of the Extruded Profile
In fact, the studied profile is mainly used in flat panel product frames. The main geometries of the studied profile include an outer diameter of 12 mm, an overall length of 19.7 mm, an outer wall thickness of only 0.7 and a middle wall thickness of 0.8 mm. According to the wear regulation of the extrusion die, the wall thickness of the hollow profile should generally be designed within a minus tolerance.
On the other hand, if eight output profiles were used, too many final output profiles create a problem in the next process control, which is dragging or pulling the initial extruded profiles.
DUnit: mm
The preheated aluminum alloy undergoes successive splitting, welding, splitting again, and the profile is finally extruded out of the bearing areas of the lower die. Figures 3 and 4 show the main structures of the lower die with the two-stage welding chamber and the non-uniform bearing length distribution, respectively. In this work, some important die features of the multi-output porthole extrusion will be evaluated in relation to the material flow and the design scheme.
The experimental four-factor, three-level alignment design using the L9 orthogonal array was conducted to study the effects of the above-mentioned die features on metal flow during multi-exit porthole extrusion, including the relative exit velocity of the extruded profile and mandrel deflection.
Thermo-Mechanical Modelling
For a specific temperature, the yield stress of the studied AA6060 increases with increasing strain rate. It is one of the products especially for extraction products from Altair Engineering Company (Troy, MI, USA). Here, the triangular prism element is used in the bracket and profile part (see Figure 7), while the tetrahedral element is adopted in the other parts.
Thus, five layers of the elements in the areas of the bearing and the profile are allocated during the engagement phase.
Results and Discussions
Figure 9 shows the through deflections of the upper die in one case of die configurations. This means that the β has the highest effect on the piercing deflection and the relative exit velocity of the extruded profile. This means that the billet angle has a slight effect on the punch bending and/or the deformation of the extruded profile.
The optimum value of the porthole chamfer angle β has a significant effect on the mandrel deflection and the relative output speed in the multi-output porthole extrusion.
Effect of Process Parameters on Fatigue and Fracture Behavior of Al-Cu-Mg Alloy after Creep Aging
Experimental
The initial state is T3, which refers to cold treatment after solution treatment followed by natural aging and then a basic stable state. Tensile testing was performed for the materials with different creep process parameters at room temperature on E45 type testing machine (MTS Systems Corporation, Eden Prairie, MN, USA) with 2 mm/min loading rate. All the fatigue tests were performed through sine wave loading at a stress ratio (R =σmin/σmax) of MPa) with a loading frequency of 10 Hz on an MTS810 testing machine (MTS Systems Corporation, Eden Prairie, MN, USA) fatigue tests at room temperature in a laboratory air environment.
Fatigue fracture surfaces of the samples deformed cyclically in fatigue testing were analyzed by a TESCAN scanning electron microscope (Tescan company, Brno, Czech Republic) to study the production and expansion of cracks.
Results and Discussion 1. Creep Behavior of Alloy
Figure 4 shows the fatigue life of Al-Cu-Mg alloy under a constant maximum load of 180 MPa after 12 hours of creep aging at different aging temperatures. Figure 8 shows the fatigue life of Al-Cu-Mg alloy under different loading after 12 hours of creep aging at 180◦C. Figures 9 and 10 show the fatigue fracture appearance of Al-Cu-Mg alloy under different stress levels (0 MPa, 210 MPa) after 12 hours of aging at 180◦C.
At the same temperature, the fatigue time of the alloy below 0 MPa is shorter than after creep ageing.
Stamping Aluminium Alloys
Experimentation
Figure 1 shows the dimensions of the round specimen used for the in-die deaf test. Figure 3a illustrates the temperature profiles used to assess in-die quenching under the forming conditions of the HFQ® technology (solid line). The quenching force in the mold was exerted by the opposing force of the gas cushion system under the entire installation.
Figure 3b shows the temperature profile of the conventional HFQ® process, which was used to investigate the effects of die clearances on the in-die quench performance.
Die Surface Temperature Calculation
To solve the partial differential equation, equation (2), finite difference method, backward time-centered spatial difference scheme described by equation (4): 4) where Δ is the time increment, Δxi is the distance increment within the workpiece or die, was used. O is a clipping error. The workpiece temperature is directly calculated using equation (6) and setting the boundary conditions to the appropriate values. The temperature on the surface of the workpiece was set to the temperature measured by the thermocouples.
The workpiece is assumed to be symmetrical, so the thermal gradient on the other side, which is the line of symmetry, is set to zero.
Results and Discussion
The workpiece thickness was 3 mm. a) Different initial workpiece temperature; (b) different contact pressure; and (c) different initial die temperatures. Figure 8 shows the effect of contact pressure on the in-the-quench time when Tquench is equal to 100◦C with different initial workpiece temperatures. The workpiece thickness was 2 mm. a) Calculated maximum die surface temperature and (b) time of cooling of workpiece to 80◦C.
Figure 11a shows the effects of backlash on in-die quenching of the workpiece.
