Stress reconstruction using finite element (FE) simulation is the critical step during residual stress measurement with contour method (CM). The quality of the FE mesh influences the accuracy of CM. There are no guidelines or suggestions to be referred to meshing the FE model for CM stress construction to improve the measurement accuracy. This study aims to distinguish the effects of FE mesh on the measurement accuracy with CM and give an optimal meshing scheme for the FE model of CM by balancing measurement accuracy and computation efficiency. A four-point bending beam was simulated to obtain the initial residual stress field. Then the CM measurement procedure was simulated with the pre-stressed bending beam model and the effects of FE mesh on the final constructed stress of CM were studied. Finally, the optimal meshing scheme in different regions of the bending beam was obtained. Results shows that the FE model employing the mapped mesh with the deformation measuring spacing in the cutting plane, mapped mesh with minimum sizes ranging from 0.01 mm to 0.09 mm in the direction normal to the cutting plane in the adjacent region of the cutting plane, and free mesh in the remaining 85
Aluminum-based amorphous alloys and composites, which have tensile and compressive strengths approximately two to three times higher than those of crystalline Al alloys and composites, are very attractive for various potential industrial applications. However, the good glass formers in Al-based alloy systems are usually found away from the eutectic points in the phase diagram and thus exhibit poor glass-forming ability. Consequently, the glass-forming compositions require cooling rates of 104–106 K/s for synthesis via rapid quenching techniques, leading to dimensional restrictions in the micrometre to millimetre range. Synthesizing glassy powders and then consolidating them in the powder metallurgy (PM) route can improve the dimensions of these materials. Many researchers have made efforts to fabricate high-dimensional Al-based metallic glasses and composites with improved mechanical properties by using different PM routes. These research efforts require further review to enhance the development of Al-based glassy alloy systems for various potential applications. Researchers working on the development of high-specific-strength materials would benefit from such reviews. This review paper provides an in-depth examination of different techniques for fabricating Al-based metallic glasses and composites, their crystallization behavior, and mechanical properties. Suggestions for future research are provided to further enhance these materials.
Bimetallic products from a liquid–solid metal alloy are challenging to cast because sufficient bonding between the two metals at the contact is difficult to obtain. By evaluating the quality of interfacial bonding using optical and scanning electron microscopy, researchers have conducted extensive research on this topic. The mechanical characteristics of bimetals, including microhardness, bonding strength, and shear strength, have also been the subject of several investigations. Based on the results of several tests, this study primarily examines bimetallic composites made from solid stainless-steel alloys and liquid grey cast iron. These advanced composite castings are primarily concerned with the quality of the connection at the joint contact. Microstructural characterisation of the interfacial region has focused on the formation of intermetallic phases and associated phase transitions near the contact.
Ferritic stainless steel is a relatively cost-effective alternative to austenitic stainless steel for general engineering applications. In this work, we report the effect of cryogenic quenching and cryogenic quenching with 10
This study investigates the behaviour of high-chromium stainless steel 304/high-carbon grey cast iron (HCSS 304/HCGCI) bimetallic metal matrix composite alloys (MMCAs) produced via green sand mold casting. The work focuses on the interaction between the molten HCGCI layer and the solid HCSS 304 functional layer during solidification. Elevated pouring temperature promoted effective metallurgical bonding by enabling substantial heat transfer from the liquid HCGCI to the solid HCSS 304 plate. During the uphill casting process, carbon and silicon diffused toward the steel, while chromium migrated from the HCSS 304 into the HCGCI. Ultrasonic non-destructive testing and destructive characterization confirmed the formation of a permanent diffusional bond at the bimetal interface. The interface was observed to be free of defects and exhibited a well-developed dual-phase microstructure comprising α-ferrite, γ-austenite, and minor martensite/carbide constituents. Post-solidification mechanical and microstructural analyses revealed that tensile strength, ductility, hardness, and impact toughness decreased with increasing HCGCI layer thickness. Overall, the findings demonstrate that HCGCI layer thickness significantly influences the mechanical performance and interfacial integrity of HCSS 304/HCGCI bimetallic systems, providing important guidance for optimizing bimetal casting processes.
