Er微合金化对1441铝锂合金微观组织和力学性能的影响

发布时间：2018-05-15 17:14

本文选题：Al-Cu-Li合金 + AlCuEr相　；参考：《稀有金属》2017年07期

【摘要】：采用铸锭冶金法制备了不同含量稀土元素Er的Al-Cu-Li合金。利用拉伸力学性能测试、扫描电子显微镜(SEM)、透射电子显微镜(TEM)及元素能谱分析(EDS)等分析测试手段,研究了Er的添加对Al-Cu-Li合金T8时效状态下的微观组织和力学性能影响。结果表明,合金在峰时效下的强度较未添加Er元素的Al-Cu-Li合金略有下降,添加0.3%Er(质量分数)的Al-Cu-Li合金的T8态峰时效屈服和抗拉强度均下降了30 MPa;添加Er元素的Al-Cu-Li合金的主要强化相仍然为δ'相(Al3Li)及S'相(Al2Cu Mg),Al-Cu-Li合金的Er元素未影响其时效析出响应速度;添加Er微合金化合金峰时效下内部有大量的δ'相和少量的S'相,而未添加Er元素的Al-Cu-Li合金峰时效下有大量的δ'相和大量的S'相,添加Er元素使峰时效态下S'相数量减少;Al-Cu-Li合金从始至终没有发现Al3Er强化相的存在证据;添加稀土元素Er,在凝固态时即可形成Al8Cu4Er相粒子,这些粒子直至均匀化和固溶热处理时仍未完全溶解于固溶体中;断口形貌分析显示添加Er元素使Al-Cu-Li合金的沿晶脆性断裂倾向增大,佐证了合金强度下降的力学性能表现。
[Abstract]:Al-Cu-Li alloys with different contents of rare earth element er were prepared by ingot metallurgy. The effect of er addition on the microstructure and mechanical properties of Al-Cu-Li alloy T8 was studied by means of tensile mechanical properties test, scanning electron microscope (SEM), transmission electron microscope (TEM) and elemental energy spectrum analysis (EDS). The results show that the strength of the alloy at peak aging is slightly lower than that of the Al-Cu-Li alloy without er element. The T8 peak aging yield and tensile strength of Al-Cu-Li alloy with 0.3er (mass fraction) decreased by 30 MPa, and the main strengthening phases of Al-Cu-Li alloy with er element were 未 'phase (Al _ 3Li) and S' -phase Al _ 2Cu MgO Al-Cu-Li alloy, and the aging response rate was not affected by er element. There are a large number of 未 'phase and a small amount of S' phase in the peak aging of er microalloyed alloy, but a large number of 未 'phase and a large number of S' phase in the Al-Cu-Li alloy without er element. The addition of er element can reduce the number of S 'phase in the peak aging state. There is no evidence of the existence of Al3Er strengthening phase in Al-Cu-Li alloy from the beginning to the end, and the Al8Cu4Er phase particles can be formed when the rare earth element er is added into the solidified solid state. These particles were not completely dissolved in the solid solution until they were homogenized and heat treated, and the fracture morphology analysis showed that the intergranular brittle fracture tendency of Al-Cu-Li alloy was increased by adding er element, which proved that the mechanical properties of the alloy decreased in strength.
【作者单位】：中南大学材料科学与工程学院;有色金属先进结构材料与制造协同创新中心;航天材料及工艺研究所;
【基金】：国家科技部“863”计划项目(2013AA032401)资助
【分类号】：TG146.21

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