TC32钛合金TIG焊接接头显微组织及力学性能研究

Study on Microstructure and Mechanical Properties of TIG Welded Joint of TC32 Titanium Alloy

利用不同成分的填充材料对TC32进行TIG焊接试验,分析接头不同区域的显微组织和力学性能。结果表明,采用TC4实心焊丝、TC32药芯焊丝和Ti-Al-V-Zr系药芯焊丝所获的焊接接头组织均不同,焊缝区宏观形貌均由上中部柱状晶区和下部等轴晶区组成,热影响区均出现三个不同的亚区;三种焊接接头的热影响区硬度显著高于母材,且每组接头的显微硬度在上、中、下区域有相同变化趋势;在焊态条件下,接头的抗拉强度与母材相当,但塑性较差。研究表明,药芯焊丝与实心焊丝相比较,药芯焊丝更容易产生气孔缺陷,导致接头的强度和韧性降低。

TIG welding test of TC32 was carried out by using different filler materials,and the microstructure and mechanical properties of different areas of the joint were analyzed.Results show that the microstructure of welded joints obtained by using TC4 solid welding wire,TC32 flux cored welding wire,and Ti-Al-V-Zr flux cored welding wire is different.The weld zone can be divided into the upper columnar zone and the lower equiaxed zone macroscopically.There are three different sub zones in the heataffected zone.The hardness of the three welded joints in the heataffected zone is significantly higher than that of the base metal,and the microhardness of each group of joints has the same change trend in the upper,middle and lower regions.Under welding,the strength of the joint is equivalent to that of the base metal,but its plasticity is poor.Compared with solid welding wire,flux cored welding wire is more prone to porosity defects,resulting in a decrease in the strength and toughness of the joint.