钛合金焊接接头疲劳裂纹声发射特征研究

摘要

Titanium alloy is extensively used in industry but the welded joints of it can easily create cracks.In this paper,the acoustic emission(AE)technique is applied to monitor the tension and fatigue damage of the titanium alloy welded ioints with different thickness.In the experimentation,the number.amplitude,degree of danger and distribution characteristics of acoustic emission incidents at titanium alloy weld;oints were recorded and analyzed.The stage theory concerning the fatigue damage acoustic emission at the titanium alloy welded joints was proposed,providing a theoretical basis for the life-cycle acoustic emission monitoring and evaluation of the service safety of titanium alloy structure.%钛合金以其良好的性能得到工业界广泛的应用,但是钛合金建造和焊接工艺极难控制,容易产生焊接缺陷.本文利用声发射技术对不同厚度钛合金焊接接头拉伸和疲劳损伤过程进行动态监测,获得了钛合金焊接接头焊缝从裂纹萌生、扩展、直至断裂过程的声发射事件数量、幅度、危险程度分布特性,提出了钛合金焊接接头疲劳损伤声发射阶段性理论,为声发射技术应用于钛合金结构服役过程的全寿命安全监测提供了理论依据.