NiTi形状记忆合金激光焊接的研究进展

Research Progress of NiTi Shape Memory Alloy Laser Welding

NiTi形状记忆合金因具有良好的形状记忆效应、超弹性、耐蚀性及生物相容性等被应用于生物医疗、航空航天及汽车等领域。激光焊接作为材料连接领域的重要技术之一,在NiTi形状记忆合金上的应用也受到了广泛关注。详细总结及分析国内外研究工作中关于NiTi形状记忆合金激光焊接接头的显微组织、力学性能、耐蚀性及生物相容性等方面的研究进展,同时分析如何提升NiTi形状记忆合金激光焊接质量的措施与机理。激光焊接过程中焊缝处镍元素的蒸发及热影响区内含镍金属间化合物的析出是导致焊接接头质量降低的根本原因,尽管通过工艺控制、焊缝合金化或焊后热处理等可提高焊接接头质量,但从目前结果来看仍有进一步提升的空间和需求。最后,结合现有研究进展及课题组的实际工作,给出NiTi形状记忆合金激光焊接未来可能的研究方向,旨在为后续的研究提供参考与借鉴。

NiTi shape memory alloys have been widely used in biomedical,aerospace and automotive fields due to their shape memory effect,superelasticity,good corrosion resistance and biocompatibility.Laser welding is one of the most important technologies in the field of material connection,and its application in NiTi shape memory alloys has attracted wide attention in recent years.The research progress on the microstructure,mechanical properties,corrosion resistance and biocompatibility of NiTi shape memory alloy laser welded joints at home and abroad is summarized and analyzed in detail.Meanwhile,the measures and mechanism of how to improve the quality of NiTi shape memory alloy laser welding are also analyzed.The evaporation of nickel in fusion zone and the precipitation of nickel-containing intermetallic in heat-affected zone are the basic reasons for the quality reduction of welded joints during laser welding.Although the quality of welded joints can be improved by process control,weld alloying or post-weld heat treatment,there is still room and demand for further improvement from the present results.Finally,the possible future research directions of laser welding of NiTi shape memory alloys are given based on the current research progress and the practical work of the research group in order to provide some reference for the follow-up research.