均匀化处理对DC铸造7X50铝合金显微组织和力学性能的影响（英文）

发布时间：2018-11-24 19:31

【摘要】：采用SEM、TEM、EDS、DSC、XRD和拉伸实验研究铸态7X50合金及其均匀化处理过程的组织演变。结果表明,铸态7X50合金相组成主要有S(Al2CuMg)、T(Al2Mg3Zn3)、Mg Zn2和少量的Al7Cu2Fe和Al3Zr相。均匀化处理过程中枝晶网和残留相逐渐减少,经(470°C,24 h)+(482°C,12 h)均匀化处理时,T相消失,S相有微量残留,Al7Cu2Fe相几乎没有变化。铸态合金的DSC曲线中在477.8°C处有一较强吸热峰,经470°C、1 h均匀化后合金的DSC曲线在487.5°C处出现一个新的吸热峰,而经482°C、24 h均匀化处理后合金在487.5°C处的吸热峰基本消失。在XRD谱中未出现T(Al2Mg3Zn3)相,这和T相与S(Al2CuMg)及Mg Zn2相相关的结论相吻合。预均匀化处理制备的板材中再结晶晶粒分数明显降低,抗拉强度和断裂韧性相对常规均匀化处理制备的板材分别提高约15 MPa和3.3 MPa·m1/2。
[Abstract]:The microstructure evolution of as-cast 7X50 alloy and its homogenization treatment were studied by SEM,TEM,EDS,DSC,XRD and tensile test. The results show that the as-cast 7X50 alloy mainly consists of S (Al2CuMg), T (Al2Mg3Zn3), Mg Zn2) and a small amount of Al7Cu2Fe and Al3Zr phases. The dendritic network and residual phase decreased gradually during homogenization. After homogenization (470 掳C ~ (10) 24 h) (482 掳C ~ (12) h), the T phase disappeared, the S phase remained in a trace amount, and the Al7Cu2Fe phase was almost unchanged. There is a strong endothermic peak at 477.8 掳C in the DSC curve of the as-cast alloy. A new endothermic peak appears in the DSC curve of the as-cast alloy at 487.5 掳C after homogenization for 1 h. The endothermic peak at 487.5 掳C basically disappeared after 24 h homogenization. There is no T (Al2Mg3Zn3) phase in XRD spectrum, which is consistent with the conclusion that T phase is related to S (Al2CuMg) and Mg Zn2. The recrystallization grain fraction of the plate prepared by pre-homogenization treatment was obviously decreased, and the tensile strength and fracture toughness of the plate prepared by pre-homogenization treatment were increased by about 15 MPa and 3.3 MPa M1 / 2, respectively, compared with those prepared by conventional homogenization treatment.
【作者单位】：东北大学材料各向异性与织构教育部重点实验室;东北轻合金有限责任公司;中南大学材料科学与工程学院;
【基金】：Project(2011KJZX1-2)supported by the Science and Technology Development Fund of Aluminum Corporation of China
【分类号】：TG166.3;TG146.21

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