搅拌摩擦焊接2195-T8铝锂合金接头的室温和低温拉伸性能

Tensile Properties at Room and Cryogenic Temperatures of Friction Stir Welded 2195-T8Al-Li Alloy Joint

在不同焊接速度(100~300mm·min-1)下对2mm厚2195铝锂合金板进行搅拌摩擦焊接,研究了焊接速度对接头室温和低温(-183℃)拉伸性能的影响,以及从室温到低温接头与母材拉伸性能变化的差异。结果表明:不同焊接速度下接头的低温屈服强度和抗拉强度均高于室温的,当焊接速度为200mm·min-1时接头的室温和低温拉伸性能最好;从室温到低温,接头的抗拉强度和塑性增幅高于母材的,低温下接头拉伸性能的提高程度高于母材的;随着焊接速度的增大,拉伸断裂位置由焊核区近后退侧处转移到之字线处。

Two-millimeter thick 2195 Al-Li alloy plates were welded by friction stir welding at different welding speeds(100-300 mm·min-1).The effects of welding speed on tensile properties of the joint at room and cryogenic(-183℃)temperatures were studied.The difference in the change of tensile properties between the joint and base metal from room temperature to cryogenic temperature was also investigated.The results show that the yield strength and tensile strength of the joint at cryogenic temperature and different welding speeds were higher than those at room temperature.When the welding speed was 200 mm·min-1,the tensile properties of the joint at room and cryogenic temperatures were the best.From room temperature to cryogenic temperature,the increase ranges of the tensile strength and ductility of the joint were higher than those of the base metal,indicating that the increase degree in tensile properties of the joint at cryogenic temperature was larger than that of the base metal.With increasing welding speed,the tesile fracture positions shifted from the near retreating side spot in the weld nugget zone to the zigzag line.