Dry sliding wear characteristics of in situ synthesized Al-TiC composites

Aluminum-based composites containing 0.06, 0.09, 0.12 fractions of insitu-synthesized TiC (Titanium carbide) particles have been prepared through in-melt reaction from Ai-SiC-Ti system following a simple and cost-effective stir-casting route. The TiC forms by the reaction of Ti with carbon which is released by SiC at temperatures greater than 1073K. However, some amount of titanium aluminide (Al3Ti) is also formed. The formation of TiC has been confirmed through X-ray diffraction studies of the composite. The hardness and tensile strength have been found to increase with increasing amount of TiC. The friction and wear characteristics of the composites have been determined by carrying out dry sliding tests on pin-on-disc machine at different loads of 9.8N, 19.6N, 29.4N, 39.2N at a constant sliding speed of the 1m/s speed. The wear rate i.e. volume loss per unit sliding distance has been found to increase linearly with increasing load following Archard's law. However, both the wear rate and friction coefficient have been observed to decrease with increasing amount of TiC in the composite. This has been attributed to (i) a relatively higher hardness of composites containing relatively higher amount of TiC resulting in a relatively lower real area of contact and (ii) the formation of a well-compacted mechanically mixed layer of compacted wear debris on the worn surface which might have inhibited metal-metal contact and resulted in a lower wear rate as well as friction coefficient.