This study focuses on a comparative analysis of mechanical behavior and microstructural characteristics of Cu matrix (C87600) based hybrid composites reinforced with SiC-Gr_p and WC-Gr_p fabricated by the stir casting process. The graphite particle percentage was kept constant, whereas the content of SiC and WC in the respective composites was varied to analyze the mechanical properties of the fabricated composites. The morphological observation was carried out by field emission scanning electron microscope (FESEM), which revealed uniform dispersion of the reinforced particles in the hybrid composites. Clear phases of SiC and WC along with the Cu alloy were identified by the x-ray diffractometer (XRD). Further, a comparative study was conducted to analyze the mechanical behavior of the Cu-SiC-Gr and Cu-WC-Gr hybrid composites. With the addition of the hard ceramic materials, the tensile behavior and microhardness of both the Cu-based MMCs were improved. The WC-Gr reinforced composites exhibited higher mechanical properties than the SiC-Gr reinforced hybrid composites. Further, the fracture surfaces were also characterized to study the tensile behavior of the fabricated copper-based hybrid composites, which shows that ductile fracture was mainly associated with both hybrid composites.

Microwave fabrication of aluminium composites has emerged as a novel and trending technique in the current industrial landscape due to its efficiency and energy-saving potential. In this study, Al-kaolin composites were fabricated using microwave energy techniques, focusing on predictive modelling of the microwave-assisted Al-kaolin composite’s wear rate and coefficient of friction (COF). The fabricated composites were evaluated for hardness, wear rate, and coefficient of friction (COF) under varying parameters. It was observed that 4 wt% kaolin is the optimal reinforcement fraction, resulting in a 34% improvement in tensile strength, while hardness showed a consistent increase up to 4 wt% Kaolin, reaching a maximum value of 96 RHC. Additionally, wear rate and COF exhibited a decreasing trend with increasing kaolin content, indicating enhanced tribological performance. The lowest wear rate of 3.2 × 10⁻⁴ mm³/Nm and COF of 0.42 were observed for the 4 wt% Kaolin composite, demonstrating improved wear resistance. To further understand and predict the behaviour of the composites, a systematic dataset was collected, and various machine learning (ML) models were trained and tested for predictive modelling of wear rate and COF. Among the trained models, XGBoost demonstrated the highest predictive accuracy, achieving 94.33% for wear rate and 94.62% for COF. A feature importance analysis revealed that the standard of distance (Sod) was the most influential parameter affecting these outputs.

The present study investigates the effects of multiple passes of equal channel angular pressing (ECAP) on magnesium alloy sheets with the assistance of an Inconel plunger along with a die setup having a channel angle of 120° and corner angle of 10° operating at a temperature of 200 °C followed by the required heat treatment processes. The microstructural analysis of the sheet samples at various stages of the multi-pass hot ECAP has shown evidence of ultrafine grain refinement (UFG) due to the occurrence of severe plastic deformation. X-ray diffraction analysis has also exhibited the presence of phases like MgZn and CeZn₃ which is supposedly responsible for the enhancement of the mechanical properties. As a result, the room temperature tensile and compressive strengths have improved by 6.12% and 6.63%, respectively, after the second pass, and 11.56% and 15.64%, respectively, after the fourth pass of ECAP. Additionally, the hardness of the sheets has increased by 6.49% and 16.64% after the second and fourth pass of hot ECAP, respectively, mainly attributed to the drastic decrease in grain size from 164 μm to 12 μm within four ECAP passes, all these with a negligible change in ductility. This success in the thermomechanical processing of Mg-RZ5 alloy sheets using a die channel angle of 120° with a minimal number of passes of hot ECAP under a controlled equivalent strain, further opens doors for incorporating optimizations and/or additional aspects so as to achieve even better grain refinements, and consequently, mechanical strength improvements thereby catering to the industrial needs of aerospace and construction areas.