Microstructure and dry sliding wear mechanism of in situ hybrid TiC–Al3Ti reinforced aluminum matrix composite
摘要
The dry sliding friction and wear properties of in situ TiC–Al3Ti synergistically reinforced aluminum matrix composites were studied by using a pin-disk friction and wear testing machine. The variation of wear rate, friction coefficient of fabricated composites with different volume fractions of Ti3AlC2 precursor was analyzed theoretically, and the corresponding wear mechanism of the composites under dry sliding friction conditions was discussed. The results demonstrate that under dry sliding conditions at 15 N, the wear rate exhibits a pronounced inverse correlation with Ti3AlC2 content, showing a 53% reduction (from 12.1 × 10−4 to 5.7 × 10−4 mm3/N m) as the volume fraction increases from 0 to 20%. The plastic flow of the matrix metal along the sliding direction in the wear subsurface layer is the basic wear feature of aluminum matrix composites, and in situ TiC–Al3Ti reinforcements can effectively prevent the plastic flow of the matrix and improve the wear resistance of the composites. With the increase of sliding distance, the deformation of the front end of the friction pin increases, and even deformation pits appear, which will strip the hard TiC and Al3Ti abrasive particles from the composite material and embed them in the matrix, which will produce furrows on the friction surface, thereby accelerating the wear of the aluminum matrix composite.