Effects of solution treatment on the microstructure and mechanical properties of Al-Cu-Mg-Ag alloy

摘要

The effects of solution treatment on the microstructure and mechanical properties of Al-Cu-Mg-Ag alloy were studied by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), differential scanning calorimeter (DSC), transmission electron microscopy (TEM) and tensile test, respectively. The results show that the mechanical property increases and then decreases with increasing the solution temperature. And the residual phases are dissolved into the matrix gradually, the number fraction of the precipitation and the size of recrystallized grains increase. Compared to the solution temperature, the solution holding time has less effect on the microstructure and the mechanical properties of Al-Cu-Mg-Ag alloy. The overburnt temperature of Al-Cu-Mg-Ag alloy is 525 ℃. The yield strength and the elongation get the best when the alloy is solution treated at 515 ℃ for 1.5 h, is 504 MPa and 12.2% respectively. The fracture mechanism of the samples is ductile fracture.