Al-Cu-Mg-Mn(-Ag)合金的时效析出与力学性能研究

Study of precipitation and mechanical properties of Al-Cu-Mg-Mn-(-Ag) alloys

通过铸锭冶金工艺,制备不同Ag含量的Al-Cu-Mg-Mn合金。采用显微观察与拉伸测试,研究其时效析出与力学性能。结果显示,Ag的添加改变了基体合金的时效析出过程,使合金的室温强度从470MPa增大到572MPa,300℃时的抗拉强度从95MPa增大到217MPa。含Ag合金在峰时效下的强化析出相由与基体共格的片状O相及少量θ′相组成。微量Ag促进Al-Cu-Mg-Mn合金强化的原因在于Ag的固溶强化和O相的沉淀硬化,其高强耐热性能主要是由于O相比θ′相具有更好的热稳定性。

A series of Al-Cu-Mg-Mn based alloys with the addition of minor Ag had been investigated using tensile testing and transmission electron microscopy （TEM）. It is shown that Ag addition modifies the artificial aging process of the alloys and increases the tensile strength from 470 MPa to 572 MPa at room temperature and from 95 MPa to 217 MPa at 300 ℃. The coherent plate-like O phase and a small amount of θ＇ phase are the predominant hardening phases in the Al-Cu-Mg-Mn alloys after peak aging. The thermal stability of the O phase is much higher than that of the θ＇ phase at high temperatures.