热处理对反向挤压AZ80镁合金组织与性能的影响

采用光学和扫描电子显微观察、X射线衍射及拉伸试验研究了反向挤压AZ80镁合金不同热处理状态下的显微组织及性能．结果表明：反向挤压AZ80镁合金热处理后析出的β－Mg17Al12相（β相）在不同热处理状态下形貌不同．经T6热处理后，口相在晶界处呈层片状析出，与挤压态相比，合金的强度稍有降低，但延伸率明显提高；经T5热处理后，卢相在晶界处仍呈层片状，而在晶内呈颗粒状，与挤压态相比，合金的强度明显提高，但延伸率降低．

Effects of heat treatment on microstructure and properties of backward extruded AZ80 magnesium alloy

Microstmctures and properties of backward extruded AZ80 magnesium alloy after different heat treatments were studied by using optical and scanning electron microscopy （SEM）, X- ray diffraction （XRD） and tensile test. The results showed that β - Mg_17 Al_12 phase precipitated in the backward extruded AZ80 magnesium alloy through different heat treatments has different morphology. After T6 heat treatment, theβ- Mg_17 Al_12 phase precipitates as lamellar morphology at the grain boundaries, strength of the alloy slightly decreases, elongation of the alloy obviously increases compared with those of the backward extruded alloy. However, after T5 heat treatment, the β -Mg17Al12 phase precipitates as usual lamellar morphology at the grain boundaries while it precipitates as granular - like morphology in the grains, and the strength of the alloy obviously increases but the elongation of the alloy decreases compared with those of the backward extruded alloy.