退火处理对轧制Mg-4Al-4RE合金组织和力学性能的影响

Effects of Annealing Treatment on Microstructure and Mechanical Properties of Rolled Mg-4Al-4RE Alloy

对Mg-4Al-4RE合金热轧板进行了不同温度的退火处理试验,采用显微组织观察、拉伸性能测试等方法研究了不同温度退火对Mg-4Al-4RE合金组织和力学性能的影响。结果表明:在220~340℃温度区间内,随着退火温度的升高,Mg-4Al-4RE合金组织中晶粒尺寸先减小后增大。经260℃退火后,合金试样组织静态再结晶完全,晶粒基本为等轴状,组织最细小均匀。随着退火温度的升高,Mg-4Al-4RE合金抗拉强度先无明显变化,后有所降低,屈服强度逐渐降低,伸长率先升高后降低。经260℃退火的Mg-4Al-4RE合金,其抗拉强度、屈服强度、伸长率分别为264.5 MPa、184.3 MPa、10.4%,综合力学性能最佳。

The annealing treatment of Mg-4 Al-4 RE alloy hot-rolled plate with different temperature was carried out. The effects of annealing at different temperatures on the microstructure and mechanical properties of Mg-4 Al-4 RE alloy were studied by means of microstructure observation and tensile properties test. The results show that, the grain size of Mg-4 Al-4 RE alloy decreases at first and then increases with the increase of annealing temperature in the temperature range of220-340 ℃. After annealing at 260 ℃, the microstructure of the alloy is recrystallized completely, and the grain is basically equiaxed, and the microstructure is the smallest and uniform. With the increase of the annealing temperature, the tensile strength of the Mg-4 Al-4 RE alloy firstly has no obvious change, and then the tensile strength of the Mg-4 Al-4 RE alloy is reduced, the yield strength is gradually reduced and the elongation first increase then decreases. The tensile strength, yield strength and elongation of Mg-4 Al-4 RE alloy annealed at 260 ℃ are 264.5 MPa, 184.3 MPa and 10.4% respectively, and the comprehensive mechanical properties are the best.