锆合金因其优良的耐腐蚀性能，常用于制造核工业器件，受到研究者广泛关注。 采用钨极氩弧焊作为焊接方法，使用 ZrTiNb 合金作为焊接材料，分别焊接了 5 、 10 、 20 mm 3 种尺寸的焊样。 所得焊接接头焊缝区微观组织为粗大的片层集束和少量的篮网状魏氏组织，组织形态与冷却速率相关；熔合区微观组织为较小的魏氏体晶粒，其与热影响区存在明显的分界线；热影响区微观组织为不规则锯齿状等轴 α 相晶粒；母材区微观组织为铸态 α 等轴晶粒。 随着焊缝距离增加，晶粒尺寸呈现递减趋势。 对焊缝进行了力学性能测试，结果表明，随着试样厚度增加，其塑性延伸强度、抗拉强度呈现先增加后下降的趋势，并在 20 mm 的厚度下出现明显下降。 10 、 20 mm 样品断后伸长率与断面收缩率相对于5 mm 试样呈现增加的趋势，但 10 mm 和 20 mm 样品性能相近。

Zirconium alloys are commonly used for manufacturing nuclear industry parts and have been widely studied by scientists because of their excellent corrosion resistance. Samples with sizes of 5, 10, and 20 mm were welded via tungsten inert gas welding, and ZrTiNb was used as the welding material. The microstructure of the weld zone is a coarse layer bundle and a small amount of basket-weave widmanstätte structure, which is related to the cooling rate. The microstructure of the fusion zone is composed of smaller widmanstätten grains, which have a clear boundary with the heat-affected zone. The microstructure of the heat-affected zone consists of irregularly serrated equiaxed α phase grains. The microstructure of the base material consists of the as-cast α equiaxed grains. As the distance from the weld zone increases, the grain size decreases. Then, the mechanical properties were tested, and the results show that as the thickness of the sample increased, the plastic extension strength and tensile strength first increases and then decreases, especially a significant decrease at a thickness of 20 mm. The elongation and reduction in the area after fracture of the 10 and 20 mm samples are similar but show an increasing trend compared to those of the 5 mm samples. This article characterizes the microstructure and mechanical properties of ZrTiNb, providing necessary data to support its engineering applications.