Wear behaviour of Al-Si alloys reinforced with in-situ formed TiB <inf>2</inf> particles

Dry sliding wear behaviour of hypoeutectic "A1-7Si" and eutectic "A1-12Si" alloys reinforced with in-situ formed TiB2 particles were compared using a pin-on-disc apparatus. The tests were conducted at different normal loads varying from 19.6 to 78.4 N. The composites were prepared by the reaction of molten alloy with K2TiF6 and KBF4 salt in a stoichiometric ratio corresponding to fixed weight fraction of TiB2. Prior to wear testing, the composites were characterized for their microstructure using X-Ray diffraction and scanning electron microscopy. The results of the wear studies indicate that incorporation of TiB2 particles into the base alloys lead to a significant decrease in their wear rates, particularly in case of the hypoeutectic alloy at higher loads. The wear surfaces and wear debris were examined to have an idea of the possible wear mechanism in these in-situ MMCs.