Influence of Thixoextrusion Parameters on Mechanical Properties of Thixoextruded 7075 Al Wrought Alloy

摘要

The main emphasis of this study is to utilize thixoextrusion process for improving extrudability of 7075 Al wrought alloy. In the present study, the influences of thixoextrusion parameters, such as initial ram speed and die bearing length, on mechanical properties of thixoextruded 7075 Al wrought alloy were investigated. The results of thixoextrusion experiments about microstructures and mechanical properties were compared with conventional extrusion results. The maximum extrusion pressure of thixoextrusion processes was seven times lower than that of conventional hot extrusion processes. The hot extruded bars show a large amount of grains which are stretched along the extrusion direction and asymmetry of grains was formed to extrusion direction, while the microstructures of the thixoextruded bar did not show any asymmetry and grains were homogeneously distributed. The hardness values of thixoextruded bar were higher than that of conventional hot extruded bar.