Experimental investigations of reciprocating wear behavior of metal matrix (Ti/TiB) composites

Abstract

In this paper, the reciprocating wear behavior of titanium–titanium boride composites with 20 and 40 (by vol. %) titanium boride (TiB) particles IS investigated in dry sliding conditions against Al2O3 ceramic balls. The trials have been observed at three loading conditions such as 5, 10 and 15 N load. The composites were processed by three powder metallurgical techniques such as spark plasma sintering (SPS), vacuum sintering (VS) and hot isostatic pressing (HIP). The electron probe microanalysis (EPMA) was used to analyze the homogeneity of Ti and boride phases in the composites. The hardness and indentation fracture resistance were evaluated using nano-indentation technique. The load–depth curves of indents for Ti–TiB shows the deviations of the modulus of elasticity within the spark plasma sintering (SPS), vacuum sintering (VS) and hot isostatic pressing (HIP).The wear resistance of the fabricated samples was analyzed using reciprocating wear tester. The SPS composite (Ti–38.5% TiB) showed lower coefficient of friction (0.07), lower wear volume (0.4368 mm3) and wear rate (0.000276 mm3/m) when compared to HIP and VS, which is attributed to the presence of fine titanium boride needles of high hardness, contributing to improving wear resistance. The surface morphology reveals that the composites processed through spark plasma sintering (SPS) and hot isostatic pressing (HIP) are subjected to minor plastic deformation. The outcome of this work is more beneficial to automotive brake pad, precision manufacturing and locomotives to avoid critical wear failures.