Influence of TiC on dry sliding wear and mechanical properties of in situ synthesized AA5052 metal matrix composites

Abstract

In this paper, aluminium metal matrix composites were synthesized through in situ process in which aluminium alloy 5052 (AA5052) and titanium carbide were used as matrix and reinforcement materials, respectively. The microstructural characterization and formation of stable TiC phases were analyzed with the help of field emission scanning electron microscope, X-ray diffraction analysis, respectively. The 9% TiC-reinforced MMCs had shown a considerable improvement, i.e. 32% increase in hardness, 78% in ultimate tensile strength and 116% increase in yield strength when compared with the base alloy. The tensile fracture of the specimens shows dimples, voids, cracks, and ridges indicating the brittle nature. Further, the dry sliding wear properties of the composites were studied with the help of a pin-on-disc wear testing machine. The composite with 9% TiC exhibited a decrease in volumetric wear loss by 24% when compared with the base alloy at a load of 30 N. With increase in the TiC content and applied load, the COF values decreased linearly for the composites. The 9% TiC-reinforced composites show an abrasive mode of wear mechanism as a result of formation of deep grooves with no plastic deformation. With the improvement obtained in the wear properties, this metal matrix composite can be considered as a replacement for the conventional brake disc material used in the automobile industry.