Zr对Al-10Zn-2.5Mg-1.6Cu合金板材组织与性能的影响

针对T6态Al-10Zn-2.5Mg-1.6Cu铝合金板材,研究了添加质量分数分别为0,0.046%,0.098%,0.151%,0.185%的Zr,铝板中合金相粒子和晶粒的组态以及板材的力学性能.结果表明,Zr含量增加对铝板中微米级T相和Al₇Cu₂Fe相粒子无明显影响,合金中未形成含Zr的结晶相,但纳米级Al₃Zr弥散相粒子数量逐渐增多.添加质量分数为0.046% Zr可细化T6态铝板等轴状Cube取向晶粒;Zr质量分数超过0.098%能抑制铝板再结晶形核,板材晶粒为纤维状,取向以Brass,S,R和Copper为主,且其体积分数随Zr含量增加而逐渐增大.Zr含量增加,T6态铝板的强度逐渐增大,而延伸率先增大后略有减小.Zr质量分数为0.151%的T6态Al-10Zn-2.5Mg-1.6Cu铝合金板材性能最佳,其抗拉强度、屈服强度和延伸率分别为706,645MPa和10.3%.

Effect of Zr Addition on Microstructure and Mechanical Properties of Al-10Zn-2.5Mg-1.6Cu Alloy Sheet

The mechanical properties and microstructure, such as the phase configuration and the grain characteristics of the T6 temper Al-10Zn-2.5Mg-1.6Cu alloy sheet were investigated with the Zr addition of 0, 0.046%, 0.098%, 0.151% and 0.185%, respectively. The results show that there is no obvious change of the micro-sized T and Al₇Cu₂Fe phases in the samples, the Zr-containing constituent phases cannot be formed and the number of Al₃Zr dispersoid nanoparticles increases with the Zr addition. Adding 0.046% Zr can refine the equiaxed Cube-oriented grains of the sample. When the Zr content exceeds 0.098%, the recrystallization nucleation can be inhibited, most of the grain shape are fibrous and the grain texture is mainly Brass, S, R and Copper orientations and its fraction increases with the Zr content. When the Zr content increases, the yield and tensile strength of the samples increase gradually and the final elongation firstly increases and then slightly decreases. The T6 temper Al-10Zn-2.5Mg-1.6Cu alloy sheet with the 0.151% Zr has the optimal performance, associated with the tensile and yield strength and final elongation of 706, 645MPa and 10.3%, respectively.