Impact of solid self-lubricant and hard ceramic reinforcements on tribological characteristics of microwave-sintered Cu hybrid composites processed by solid-state mixing technique

Abstract

In this experimental investigation, new sequence of Cu-X wt% SiC (X = 0, 5, 10, and 15) -Y wt% Gr (Y = 5 and 10) metal matrix hybrid composites was effectively manufactured by solid-state mixing (powder metallurgy) technique through a novel microwave sintering process. The influence of hard ceramic reinforcement SiC content and soft self-lubricating reinforcement Gr content on the mechanical and tribological properties of copper hybrid composites was analysed. Using the pin-on-disc tribometer the results of the wear resistance and sliding friction properties of all produced microwave-sintered composites were assessed. Weight percentages of SiC, applied load, sliding distance, and sliding speed are the testing parameters considered for tribological characterization. During dry sliding, the loss in mass was recorded as wear loss. It was observed that with an increase in the SiC weight percentage, the wear resistance enhanced monotonically with hardness. The microwave-sintered cylindrical composites have been characterized by X-ray diffraction. Optical microstructural studies confirmed the distribution of both the reinforcements was homogeneous on the base matrix copper. The tribological performance of the hybrid composite containing 10 wt% graphite and 15 wt% SiC showed better to that of the other manufactured composites. The kind of wear mechanisms was recognized through morphology of the worn-out surfaces and the wear debris by scanning electron microscope. This experimental analysis revealed that the hybridization of both hard reinforcement like SiC and soft reinforcement like Gr get better wear resistance of copper composites considerably through microwave sintering processes.