焊缝熔深对2219铝合金TIG焊接头拉伸性能的影响（英文）

采用数值模拟和实验的方法研究焊缝熔深对2219铝合金TIG焊接头拉伸性能的影响。结果表明,当其他几何参数一致时,在一定范围内,盖面焊缝的熔深越大,接头的拉伸性能越低。较大的盖面焊缝熔深可造成焊趾处更集中的应力,导致接头更容易断裂。根据必要的假设提出的一种分析盖面熔深与接头拉伸性能间数学关系的模型验证了实验结论。盖面焊缝熔深的减少可通过降低焊接电流、氦气流量或增加焊接电压来调控。

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

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。

Effects of Post-weld Heat Treatment on Microstructure, Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state,each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases.After the post-weld heat treatment,both the amount and the size of the eutectic structure orθphases decreased.Correspondingly,both the Cu content inα-Al matrix and the microhardness increased to a similar level in each region of the joint,and the tensile strength of the entire joint was greatly improved.Post-weld heat treatment played the role of solid solution strengthening and aging strengthening.After the post-weld heat treatment,the weld performance became similar to other regions,but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect.The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties,and the specimens randomly crack in the weld zone.