The effect of the die shape on the hot extrudability and mechanical properties of 6061 Al/Al_2O_3 composites

摘要

Metal matrix composites (MMCs) fabricated by thecompocasting process show a homogeneous distribution of thereinforcing fiber in me matrix Microstructural observation of hotextruded MMCs reveals that as the extrusion ratio increases, thefiber alignment becomes improved, but fiber fracture occurs more severely.The mechanical properties of hot extruded MMCs are better thanthose of the matrix metal, with the exception of the elongation atfailure, and are not influenced significantly by the extrusiontemperature. The tensile strength and hardness of MMCs areimproved to a greater degree by hot extrusion using a constant-strain-rate die. Also, there exists a critical extrusion ratio that givesmaximum strength, which is 5.44 in this study. Additionally,fractograph of the tensile specimen of extruded MMC indicates theductile fracture behavior of the matrix.