TC4钛合金摩擦焊接头的力学性能及显微组织

对钛合金TC4（Ti-6Al-4V）摩擦焊接性能进行了较详细的试验分析。结合摩擦焊接参数的优化选择，叙述了该合金摩擦焊接过程的特点，讨论分析了其焊接接头的力学性能及焊合区的显微组织结构。试验结果表明，该合金具有良好的摩擦焊接性，在无特殊保护措施的条件下，优化工艺，可获得良好的焊接接头。由于TC4钛合金导热系数小，热塑性高，容易氧化，摩擦焊亦选用较小的规范参数。焊合区硬度略低于母材，拉伸度样断于母材，拉伸、冲击断口均表现出明显的韧性断裂特性。力学性能数据表明，用优化的规范参数，TC4钛合金可获得等强、等韧甚至超强、超韧于母材的摩擦焊接接头。TC4钛合金摩擦焊接接头焊合区组织为细密的网蓝状组织，焊合区与母材过渡区为双态组织。

Mechanical Properties and Microstructure of Titanium Alloy Friction Welded Joint

Friction welding weldability test about titanium alloy TC4(Ti 6Al 4V) was done in detail.Concerning the optimum selection of the parameters,the feature of the TC4 alloy friction welding process was recounted and the mechanical properties and structure of the joint was analyzed.The test result shows that TC4 alloy has good weldability.Without particular protection step,good welded joint can be gotten by means of optimum technological parameters.Because TC4 alloy has low heat conductivity,high heat plasticity and good oxidability,low welding parameters should be selected.The hardness of the weld area is a little lower than that of the base metal.The tension specimen was broken on the base metal.Fracture of tension and impact test show obviously tough break characteristic.With the optimum parameters,equal strength and equal plasticity or even high strength and high plasticity friction welded joint of TC4 alloy can be gotten.The weld area of the joint are closely woven and netted structures.The transitional zone between the weld area and the base metal is double stated structures.