摘要:
采用低功率脉冲激光对厚度为0.2mm的TiNi形状记忆合金进行了对接焊,研究了接头的抗拉强度、断裂应变、相变过程和形状记忆效应.试验发现,低功率脉冲激光能够实现薄片状TiNi合金的良好焊接.冷轧态TiNi合金焊后接头的强度达到母材的97%,断裂应变为母材的95%,对接头进行焊后退火处理其强度有所提高,高于冷轧态母材、达到退火态母材的63.6%,断裂应变为退火态母材的82.5%.冷轧态TiNi合金焊接接头经焊后退火处理,其相变过程和退火态母材接近,形状记忆效应基本和退火态母材相同.
Abstract:
The butt welding of 0.2 mm thick TiNi shape memory alloy(SMA) sheet was carried out by using low power impulse laser,and the tensile strength,fracture strain,phase change process and shape memory effect of welded joint were studied.The results show that using low power impulse laser can realize good butt welding of TiNi SMA sheet.The tensile strength of welded joint of cold rolled TiNi SMA achieves 97% of base metal,and fracture strain achieves 95% of base metal.When the welded joint is annealed after welding,its tensile strength is somewhat increased and higher than cold rolled TiNi SMA base metal.The tensile strength of welded joint with post weld annealing treatment achieves 63.6% of annealed TiNi SMA base metal,and fracture strain achieves 82.5%.The phase change process of welded joint with post weld annealing treatment is almost the same with annealed base metal.When the welded joint of cold rolled TiNi SMA is annealed after welding,its phase change process is close to annealed base metal,and its shape memory effect is almost the same with annealed base metal.
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