Investigation of Tribological Behavior on the Mechanical Properties of TiB2, Al2O3 Reinforced AA6061 Matrix Sintered Hybrid Composites

Abstract

Hybrid composites consisting of AA6061 matrix reinforced with TiB2 (2, 4, 6, and 8 wt. %), Al2O3 (2 wt.%) particles were produced by the sintering process. In comparison to the base material AA6061, the composite produced had improved mechanical properties. The mechanical properties in the sintered composite samples such as tensile strength and hardness, are measured and compared to the wear-tested specimen. Optical micrographs reveal that composites were riddled with defects like blowholes, pinholes, and improper bonding between the particulates before sintering. However, the post-sintered optical micrograph showed that the defects were greatly suppressed. Micrographic images revealed the changes in surface characteristics before and after wear. Until a sliding distance of 260 m, the wear rate of the hybrid composites was kept lower than that of the base material. The coefficient of all the composite materials produced in this study was less than that of the base material. The results reveal that the hardness of hybrid composites having 4 and 6 wt. % of TiB2 particulates increased by 5.98 and 1.35% respectively. Because of the frictional heating during the wear test, the tensile properties lowered by up to 49.6%. It is concluded that the hybrid composites having 4 and 6 wt. % of TiB2 particulates exhibited less wear rate for extended sliding distance, good hardness, moderate tensile strength, and decent elongation percentage compared to the base material counterparts.