Microstructure and properties of TiC–Ti5Si3 reinforced copper matrix composites

Abstract

In this study, Ti5Si3 single-phase and TiC–Ti5Si3 hybrid phases reinforced copper matrix composites with different volume fractions were prepared by melt reaction. The microstructures and mechanical properties of the composites were analyzed to investigate their wear and tensile mechanisms. The wear resistance of the composite materials exhibits a non-linear behavior with increasing load, initially decreasing and then increasing, reaching its lowest point at 7.35 N. At higher loads, such as 9.8 N, the composites form a more stable and effective wear-resistant layer, exhibiting the positive impact of the reinforcing phase on wear resistance. Furthermore, as the content of the reinforcing phase increases, the brittleness of Ti5Si3 also increases, along with the expansion of the interface between the reinforcing phase and the matrix. This results in a transition of the wear mechanism from delamination wear to abrasive wear and an increased likelihood of spalling under shear forces. Therefore, the composite material achieves optimal wear resistance when the Si content is at 1%. In addition, the TiC and Ti5Si3 phases within the Cu matrix not only effectively bear the load but also impede crack propagation, resulting in a shift in the fracture mode of the composites from ductile fracture to cleavage fracture or quasi-cleavage fracture as the reinforcement content increases. Finally, hot rolling proves to be an effective method for refining the reinforcement and improving its uniformity, leading to significant enhancements in tensile strength and ductility. However, the reinforcement causes a disruption in the continuity of the matrix, resulting in a reduced elongation in the composite material with a Si content of 1% after the hot rolling process.