The effect of matrix hardening on the strength of the extruded 2024Al/Al18B4O33w composite

Abstract

The hot extrusion is used to align the whiskers and improve the strength of the 2024Al/Al18B4O33w composite. The effects of extrusion and T6 treatment on the microstructure, matrix hardening and tensile properties of 2024Al/Al18B4O33w composite are investigated. The results show that the nano-hardness of matrix in the extruded composite increases. The yield strength increases and then reduces with increasing extrusion ratio. The alignment of whiskers along the extrusion direction and matrix hardening result in the increase in yield strength of the extruded composite. Compared with the continuous decrease in effective average aspect ratio of whiskers, matrix hardening has the obvious effect on the strengthening efficiency and the increase in σUTS−σYS of the extruded composite. The T6 treatment leads to the improvement in strength of the extruded composite. The extruded-T6 composite with the higher yield strength of the matrix has the lower hardening capacity.