耐热铸造Al-Cu-Mn合金高温力学性能与微观组织

Properties and Microstructure of Al-Cu-Mn Heat-resistant Alloy at High Temperature

针对一种Al-Cu-Mn耐热铸造铝合金,研究了在室温、250℃和300℃下以及不同温度稳定化处理后的力学性能和不同热处理状态下的微观组织。结果表明,随着试样测试温度或高温稳定化处理温度升高,合金抗拉强度下降,伸长率升高,在300℃稳定化处理100 h后的抗拉强度最低,但也超过200 MPa。合金的主要强化相是θ相、S相、T相,高温稳定化处理后,θ相、T相发生粗化,从而导致合金强度下降。

The mechanical properties of an Al-Cu-Mn heat-resistant cast aluminum alloy at room temperature,250℃,300℃and after stabilization treatments under different temperatures as well as microstructure under different heat-treated states were investigated.The results indicate that the tensile strength of alloy is decreased and the elonga⁃tion is increased with the increase of test temperature or stabilization treatment temperature.The tensile strength reaches the minimum after stabilization at 300℃for 100 h,which also reaches over 200 MPa.The main strengthening phases of alloy areθphase,S phase and T phase.After high temperature stabilization treatment,the morphologies ofθand T phase are coarsened,resulting in a decrease in strength of alloy.