Sliding wear of LM25 aluminium alloy with 7.5% SiC+2.5% TiO 2 and 2.5% SiC+7.5% TiO 2 hybrid composites

Abstract

An experimental investigation on the wear behavior of aluminium alloy LM 25 and its composites reinforced with 7.5% SiC + 2.5% TiO₂ and 2.5% SiC + 7.5% TiO₂ is carried out to ascertain which constituent is having more influence on the metal matrix composites. The hybrid composite material is prepared by stir casting process. The wear and frictional properties of hybrid metal matrix composite are studied by performing dry sliding wear test using a pin on disc wear tester. The experiments are conducted at a constant sliding velocity of 1.04 m/s and a sliding distance of 628 m over various loads of 3, 4 and 5 kg. The result shows that, the reinforcement SiC and TiO₂ has improved the wear resisting property of LM 25 alloy composite. The results also indicate that the three-fourth volume fraction of the TiO₂ in a 10% volume fraction of reinforcement has better wear and frictional property than the three-fourth volume fraction of SiC. The coefficient of friction decreases with the increasing load and particle reinforcement. The microstructure analysis reveals that SiC and TiO₂ particulate are uniformly distributed in the matrix. The wear surfaces are examined by scanning electron microscope which indicates an abrasive wear mechanism due to hard ceramic particles exposed on the worn surface.