摘要
Microstructural evolution and its effect on mechanical properties in different regions of 2219-C10S aluminum alloy tungsten inert gas(TIG)welded joint were analyzed in detail.In weld zone(WZ),α+θeutectic structure formed at grain boundaries with no precipitates inside the grains.In partially melted zone(PMZ),symbiotic eutectic or divorced eutectic formed at grain boundaries and needle-likeθ′phases appeared in the secondary heated zone.In over aged zone(OAZ),the coarsening and dissolution ofθ′phases occurred and mostθ′phases transformed intoθphases.In general heat affected zone(HAZ),θ′phases coarsened.Factors such as the strengthening phases,the grain size,the Cu content in matrix and the dislocation density can affect the mechanical properties in different regions of the joint.Moreover,a model describing the relationship between mechanical properties of the material and the volume fraction of precipitates,the average diameter of precipitates and the concentration of soluble elements was proposed.
详细分析2219-C10S铝合金TIG焊接接头各区显微组织演变及其对力学性能的影响。结果表明,在焊缝区,晶界形成α+θ共晶组织,晶内无析出相;在部分熔化区,晶界形成共生共晶或离异共晶,二次受热区晶内析出针状θ′相;在过时效区,θ′相发生粗化与溶解,大部分θ′相转化成θ相;在热影响区,θ′相发生粗化。强化相、晶粒尺寸、基体Cu含量和位错密度等因素可影响接头各区力学性能。此外,提出一种可用于描述材料力学性能与析出相体积分数、析出相平均直径、固溶元素浓度之间关系的模型。
基金
Project(U1637601)supported by the Joint Funds of the National Natural Science Foundation of China。
