轧制温度对Mg-Gd-Y-Zr合金组织和力学性能的影响

Effect of rolling temperature on microstructure and mechanical properties of Mg-Gd-Y-Zr alloy

为研究轧制温度对Mg-8.3Gd-2.6Y-0.4Zr(质量分数/%)合金显微组织和力学性能的影响,将500℃预轧制所得板材在200、300、400℃进行二次轧制变形。结果表明:200℃二次轧制变形使合金中引入大量位错和孪晶;合金在300℃二次轧制过程中,于晶界和晶粒内部分别形成大量的β相和β′相,而400℃二次轧制仅使合金晶界处形成粗大的β相;不同温度下二次轧制变形均使预轧制板材的基面织构强度增大,二次轧制温度越低,基面织构越强;不同温度下二次轧制变形均使预轧制板材的强度提高,二次轧制温度越低,合金强度提高越显著;经200℃二次轧制得到的合金具有331 MPa的最高屈服强度。

In order to investigate the effect of rolling temperature on the microstructure and mechanical properties of the Mg-8.3Gd -2.6Y-0.gZr alloy, a pre-rolled Mg-8.3Gd-2.6Y-0.4Zr （mass fraction/%） alloy sheet was further rolled at 200, 300 and 400 %, respectively. Results show that the further roiling at 200 ℃ produces numerous dislocations and twins in the alloy. And rolling at 300 ℃ induces extensive precipitations of both 13＇ phase in the interior of grains and 13 phase on grain boundaries, while only the coarse 13 precipitates on grain boundaries are detected after rolling at 400 ℃. Besides, the further roiling increases the texture intensity of the alloy. The higher rolling temperature corresponds to the lower texture intensity. Generally, the further rolling deformation increases the strength of the initial alloy, and the lower rolling temperature results in the more improvement in strength. The sample rolled at 200 ℃exhibits the highest TYS of 331 MPa.