Effects of hot extrusion and heat treatment on mechanical properties of in-situ( Al_3Zr+ZrB_2)_p/6063Al composites

Aluminum matrix composites reinforced by in-situ Al3 Zr and ZrB2 particles were successfully fabricated from Al-KBF4-K2ZrF6 system via direct melt reaction. Extrusion processing and heat treatment were performed to find the effect of hot extrusion and heat treatment solution for the highestfigure of the tensile strength to the composite. The morphologies of the in-situ particles and mechanical properties of the composite were investigated by SEM,EDS,XRD,OM and tensile tests. The results show that both extrusion and heat treatment has a positive influence on the microstructure and tensile strength of the composite,which increases 6% and 20% respectively. And the influencing sequence of the heat treatment parameters on the tensile strength was: solution treatment temperature,aging temperature and aging time. The specimen with solution treatment for 4hat 723 K and aging temperature for 4 h at 423 K reaches the highest figure of tensile strength with moderate extensibility loss.