Self-propagating high-temperature synthesis of Ti₃SiC₂/diamond composites in a microwave field with the assistance of Ni-Al powders

In this study, a self-propagating high-temperature synthesis (SHS) process was initiated within a microwave field, utilizing the combustion of Ni-Al powders to fabricate Ti3SiC2-based diamond composite materials. To promote the formation of Ti3SiC2, aluminum powders were incorporated into a mixture of elemental Ti, Si, and C powders, along with diamond abrasives, as the raw materials. The effects of aluminum addition and diamond particle size on the phase composition and microstructure of the composites were thoroughly investigated. Under microwave-assisted SHS conditions, the ignition time for the SHS process was significantly reduced to 374 s when the premixed molar ratio of Ti:Si:C:Al was optimized to 3:1:2:0.4, and combined with a diamond particle size of 140/170 mesh. X-ray diffraction (XRD) analysis revealed that the highest conversion rate of Ti3SiC2, reaching 54%, was achieved at a molar ratio of Ti: Si: C: Al = 3:1:2:0.2 and a diamond particle size of 140/170 mesh. Additionally, the maximum wear ratio of 712.85 was observed when the diamond size was 70/80 mesh, with a Ti:Si:C:Al molar ratio of 3:1:2:0.2. Scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS) revealed that the fracture surface exhibits appropriate interface interactions between the matrix and diamond particles, which supports controlled grain retention and promotes self-sharpening behavior that is critical to diamond grinding wheel performance. The high efficiency of the SHS synthesis process in the microwave field, along with the wear resistance of MAX-phase-bonded diamond composites, provides a promising pathway to reduce manufacturing costs and energy consumption in the production of diamond wheel.