Influence of the hard coated B_4C particulates on wear resistance of Al-Cu alloys

摘要

In the present study, sliding wear tests were carried out on different sizes and volume fractions of coated B_4C particles reinforced 2024 aluminum alloy composites fabricated by a squeeze casting method. Micro structural examination showed that the B_4C distributions were generally homogeneous in the matrix while some particle clusterings were observed at relatively high particle containing composites. As com pared to the 2024 Al matrix alloy, the hardness of the composites was found to be greater. It is observed that the wear resistance of the composites was significantly higher than that of the unreinforced alumi num alloy, and increased with increasing B_4C particles content and size. The hard B_4C particles act as a protrusion over the matrix, carries a major portion of the applied load and protect the abrasives from penetration into the specimen surface. Combination of rough and smooth regions is distinguished on the worn surface of the composites. The depth and number of grooves in composites decreased with increasing volume fraction of B_4C particles, and the worn surfaces of composites were relatively smooth.