钛合金/铝合金搅拌摩擦焊接头的显微组织

Microstructure of friction stir welding joint between titanium and aluminum dissimilar alloys

采用搅拌摩擦焊对TC1钛合金和LF6铝合金异种金属进行焊接,采用金相、扫描电镜和能谱观察分析焊接接头的组织。结果表明:搅拌摩擦焊接头中,钛合金母材与焊核的界面凸凹不平,边界处存在白亮颗粒,而铝合金母材与焊核的界面光滑、平整;焊核区铝合金基体上分布大小不等的颗粒,这种颗粒有两种类型,一种颗粒的尺寸较小、呈细长条状,另一种颗粒尺寸较大,整体呈暗灰色、边缘有少量发亮的条带。两种颗粒中均有Ti-A1金属间化合物存在;钛合金/铝合金异种材料焊接时,搅拌头的磨损很严重,在焊核和铝合金母材的边界存在搅拌头磨损后脱落的颗粒。

The dissimilar metals of TCl titanium alloy and LF6 aluminum alloy were jointed by friction stir welding （FSW）, and the microstructure of welded joint was studied by optical microscopy, scanning electron microscopy （SEM） and energy disperse spectroscopy （EDS）. The results show that, in the welded joint, the interface between titanium alloy base metal and nugget is rough and uneven, and there are bright particles on the boundary. The interface between aluminum alloy base metal and nugget is smooth. Many particles with different grain size on the aluminum alloy base metal varying sizes on it. The particles in nugget can be divided into two types, one type is long narrow and small, the other type is relative large, dimmed and with several alight band on the edge. Ti-Al intermetallic compounds exist in the two types of particles. The pin tool is worn seriously and there are particles worn from pin tool in the interface between aluminum alloy base metal and nugget.