基于PLC的镁合金厚板搅拌摩擦焊的焊缝组织与性能

Microstructure and properties of the welding joint of magnesium alloy thick plates by PLC-based friction stir welding

分别采用普通搅拌摩擦焊和基于PLC的搅拌摩擦焊方法进行了16 mm厚AZ31镁合金厚板的焊接,并对焊接接头进行了无损探伤、XRD、SEM和力学性能等测试。结果表明,与普通搅拌摩擦焊相比,基于PLC的搅拌摩擦焊有助于显著细化接头焊核区的晶粒,明显改善焊接接头的力学性能,室温抗拉强度从207 N/mm2增加至251 N/mm2,接头系数从80%增加至97%,室温伸长率从8.1%增加至9.2%。

The traditional friction stir welding and PLC-based friction stir welding are used to weld 16mm thick plates of AZ31 magnesium alloy. Non-destructive testing,XRD, SEM and mechanical properties testing are carried out on welded joints of the plates. The results show that compared with traditional friction stir welding, PLC-based friction stir welding contributes more to grains refinement in the nugget zone and improvement of mechanical properties. The tensile strength at room temperature, the joint coefficient and the elongation. at room tempera- ture increase from 207 N/ram2 to 251 N/mm2, from 80% to 97 %, and from 8. 1% to 9.2 %, respectively.