热轧及退火处理对Mg-10Gd-3Y-0.3Zr合金显微组织及抗压强度的影响

Influence of Hot Rolling and Annealing Treatment on Microstructure and Compressive Stress of Mg-10Gd-3Y-0.3Zr Alloy

为了探究Mg-10Gd-3Y-0.3Zr高温热轧及退火处理对合金显微组织及抗压强度的影响,文中利用光学金相显微镜观察高温轧制板材的显微组织,分析晶粒尺寸大小和动态再结晶程度.研究结果表明:随着变形量增加,晶粒尺寸显著减小,当下压量为60%时晶粒尺寸大小均匀,约为60μm,孪晶密度高;下压量达到60%之前,晶粒粗大,孪晶密度低,超过60%之后,再结晶晶粒逐步取代变形晶粒,晶粒尺寸减小,孪晶几乎消失.退火处理能够显著提高轧制板材的抗压强度,其中175℃×3h退火处理后强化效果明显,抗压强度达到424MPa,退火温度超过175℃后,强化效果开始减弱.

In order to explore the influence of hot rolling and annealing treatment on the microstructure and compressive strength of Mg-10Gd-3Y-0.3Zr alloy,an optical metalloscope was used to observe the microstructure of the material rolled at a high temperature and analyze the grain size and the degree of dynamic recrystallization.The result shows that with the deformation increasing,the grain size of Mg-10Gd-3Y-0.3Zr alloy decreases significantly;when the rolling reduction reaches 60%,the grain size is uniform,about 60μm,and the density of twin crystal is high;when the rolling reduction is less than 60%,the grain size is coarse and the density of twin crystal is low;when the rolling reduction exceeds 60%,the recrystallized grains gradually replace deformed grains,the grain size decreases and twin crystal almost disappears.Annealing treatment can significantly increase the compressive strength of the rolled plate.After annealing treatment at 175℃for 3 hours,the strengthening effect becomes obvious and the compressive strength is 424 MPa.When the annealing temperature exceeds 175℃,the strengthening effect begins to decrease.