Dry sliding wear behaviour of A356-TiB<SUB align="right">2/TiC in-situ composites at ambient and elevated temperatures

Abstract

A356-TiB2/TiC in-situ metal matrix composites have been developed through reactions between liquid aluminium and various chemicals, such as potassium hexa fluorotitanate (K2TiF6), potassium tetra fluoroborate (KBF4), and graphite (C), through flex assisted synthesis. In the present investigation, the distinct quantities of halide salts were added into molten aluminium to obtain 0, 2.5, 5, and 7.5% of TiB2/TiC-reinforced composites. The fabricated composites were examined by a scanning electron microscope (SEM) energy dispersive analysis (EDAX) X-ray diffraction analysis (XRD) and micro-hardness tests to evaluate the effects of adding the reinforcement. The wear behaviour of A356-TiB2/TiC composites was studied using a pin-on-disk apparatus. The influence of wt% of the reinforcement, sliding velocity, normal load, and temperature on wear rate (WR), coefficient of friction (COF), specific wear rate (SWR), and wear rate per unit wt% of the reinforcement. The worn out surfaces of A356-TiB2/TiC composites were carefully analysed with an SEM. TiB2 and TiC particles improved the wear resistance of composites at ambient and elevated temperatures. This result reveals that at elevated temperatures, the pure alloy was subjected to adhesive wear, whereas oxidation wear was more dominant in A356-TiB2/TiC composites.