MICROSTRUCTURE AND MECHANICAL BEHAVIOR OF 6061 AL ALLOY REINFORCED WITH SIC NANOPARTICLES PROCESSED BY EXTRUSION AND COLD ROLLING

摘要

A 6061 Al alloy composite reinforced with 15wt% SiC particles has been produced by powder processing routes followed by extrusion and cold rolling. The microstructure and mechanical properties were compared with the 6061 Al alloy produced by powder compaction followed by extrusion. Microstructural characterization and mechanical property tests have been carried out in asextruded and as-rolled conditions. No interfacial reactions were promoted during the fabrication procedures. A significant realignment of SiC particles were obtained after cold rolling. The particle free bands in as-extruded sample have disappeared with further rolling passes, resulting in a more homogeneous distribution of SiC particles. The microhardness values of the 6061Al/SiC_p sample are much higher than those of the 6061Al sample. With increasing rolling reductions, the microhardness values of both the composite and 6061Al alloy increases until reaching a limit value. The three-point bending strength of as-rolled composite has surpassed the as-extruded composite by a significant amount.