Mg含量对2A14铝合金组织和力学性能的影响

Effect of Mg content on microstructure and mechanical properties of 2A14 aluminum alloy

借助光学显微镜(OM)、扫描电镜(SEM)、维氏硬度计、拉伸和冲击试验机等测试设备研究了不同Mg含量对2A14铝合金显微组织和力学性能的影响。结果表明,随着Mg含量的增加,时效态合金基体中剩余结晶相明显增多,强度先增加后降低,而强度最高时冲击性能略有降低。Mg含量的增加会促进Cu-Mg团簇的形成,为后续θ′和Q′相提供形核位点,使其数量显著增加,强度随之提高,但过多的Mg会使基体中剩余结晶相(Al_(2)Cu、AlCuMgSi、AlSiMnFe等)显著增加,造成应力集中,降低冲击性能和拉伸性能。

Effect of different Mg contents on microstructure and mechanical properties of 2 A14 aluminum alloy were studied by means of optical microscope(OM),scanning electron microscopy(SEM),hardness tester,tensile tester and impact tester.The results show that with the increase of Mg content,the residual crystalline phase in the aged alloy increases obviously,the strength increases first and then decreases,and the impact property decreases slightly when the strength is the highest.The increase of Mg content promotes the formation of Cu-Mg clusters,which provides nucleation sites for subsequentθ′and Q′phases,so that the number ofθ′and Q′increases significantly and the strength increases accordingly.However,excessive Mg content significantly increases the residual crystalline phases(Al_(2)Cu,AlCuMgSi,AlSiMnFe,etc),resulting in stress concentration,which reduces impact property and tensile properties.