采用等离子焊接工艺，在Q235B钢基板上依次熔覆铜层和TA0钛层，研究了焊接电流（85，90，95，100，105 A）对钛/钢异种金属焊接接头成形性能及显微组织的影响。结果表明：焊接电流大于90 A时，该焊接工艺能够有效抑制脆性相和焊接裂纹的形成；随焊接电流增大，熔覆层中未熔合区域减少，厚度均匀性提高；焊接电流为100 A时，熔覆层成形性最好，钛层、铜层、钢基板之间呈良好的冶金结合；钛层、铜层的显微组织分别为细针状树枝晶和柱状树枝晶，钢基体热影响区为细小的珠光体+铁素体相和粗大的铁素体相；不同焊接电流下，铜/钛界面附近硬度均最高，该区域钛、铜晶粒相互交错，有大量CuTi₂、CuTi等低脆性金属间化合物析出。

Copper layer and TA0 titanium layer were sequentially deposited on the Q235B steel plate by plasma arc cladding. The effect of welding current (85, 90, 95, 100, 105 A) on formability and microstructure of the titanium/steel dissimilar metal welded joint was studied. The results show that this welding process could effectively suppress the formation of brittle phases and welding cracks when the welding current was higher than 90 A. With increasing welding current, the unfused area of the cladding layer decreased and the thickness uniformity increased. The cladding layers had the best formability at welding current of 100 A; the titanium layer, copper layer and steel substrate showed good metallurgical combination; the microstructures of titanium layer and copper layer were fine needle dendrite, columnar dendrite, respectively, and that of the heat-affected zone in steel substrate was fine pearlite + ferrite phase and coarse ferrite phase. At different welding currents, the hardness near the copper/titanium interface was the highest. In this area, the titanium and copper grains were interlaced, and a large number of low brittle intermetallic compounds such as CuTi₂ and CuTi precipitated.