Investigation on the characterization of hot extruded AA7075 based metal matrix composites developed by powder metallurgy

Abstract

Higher compressive stress and greater density after extrusion contribute to stronger bonds, which in turn improves mechanical and tribological properties were analyzed. In order to minimize manufacturing defects, a cosine-profiled die with mathematically precise contours was used in the thermo mechanical process. It was requested that more mechanical characterization tests, such as a compression testing and a three-point bending test, be directed to better define the material’s density, hardness, and ductility. Before and after extrusion, the prepared AMCs were put through pin-on-disc (POD) wear testing, during which the RPM of the counter disc, load (N) and track diameter (mm) were varied to simulate different two-body dry sliding wear behaviors. Hot extrusion of AA7075 aluminium matrix composites (AMCs) was investigated for its effect on the materials’ mechanical and tribological properties. These AMCs were manufactured by controlled atmospheric sintering, powder metallurgy and double axial cold compaction. The finely dispersed graphite (Gr) particles shear off at the tribo-surface, creating a solid lubricant that slows the rate of wear. The wear mechanism was found to be more complex when the loading and sliding velocities were increased.