大厚度扩散焊NLU成像检测技术

摘要

Diffusion bonding (DB),as a solid state welding,has been increasingly applied in aeronautical and space industries.The defects induced in thick DB plate are much more difficult to be found out by conventional ultrasonic techniques because of their characteristics of kiss-bonding,small-size and distribution and high ultrasonic attenuation.A new ultrasonic imaging technique,which is based on non-linear ultrasonic (NLU) components of the received signals resulted from diffusion bonding interface,is developed into nondestructive evaluation (NDE) of thick diffusion bonded plate.The experimental results show the powerful ability to the NDE of thick plate diffusion bonds by using the NLU visual method.The maximum thickness of diffusion bonding is up to 70mm.%针对钛合金大厚度扩散焊,基于非线性超声(Non-linear ultrasonic,NLU)原理,构建了一种NLU成像方法和检测系统,设计制备了不同的大厚度扩散焊试件,进行了NLU成像检测试验分析.检测结果表明,采用NLU成像检测方法,可实现钛合金大厚度扩散焊的超声可视化检测,最大检测厚度可达70mm.