钛合金扩散焊水浸超声相控阵相位迁移成像方法

Ultrasonic Phased Array Phase Shift Migration Imaging Method for Titanium Alloy Diffusion Welding

钛合金广泛应用于航空航天等工业制造领域,扩散焊是钛合金构件连接的一种主要方式,连接质量对构件的安全使用非常重要。针对钛合金扩散焊典型内部缺陷的检测开展水浸超声相控阵检测研究。首先根据高斯叠加定理研究不同水深对相控阵声场的影响,以确定适合的水层厚度;其次建立含典型缺陷钛合金扩散焊有限元模型,模拟水浸超声相控阵检测过程并采集检测数据;最后将超声相控阵平行聚焦扫描数据根据相位迁移原理进行频域合成孔径成像。研究结果表明:利用超声相控阵聚焦扫描数据进行双介质频域合成孔径成像,相比相控阵传统B扫成像,除检测出传统成像方法无法成像的直径0.2 mm微孔缺陷外,对比率平均提升了6.39 dB,缺陷定位精度在1.3%以内,该方法可为钛合金扩散焊缺陷的水浸超声相控阵检测提供理论指导。

Titanium alloy is widely used in aerospace and other industrial manufacturing fields.Diffusion welding is a main way of component connection,and the quality of connection is very important for the safe use of components.Aiming at the detection of typical internal defects in diffusion welding of titanium alloy,the research of water immersion ultrasonic phased array detection was carried out.Firstly,the influence of different water depth on phased array acoustic field is studied according to Gauss superposition theorem to determine the suitable water layer thickness;Secondly,the finite element model of diffusion welding of titanium alloy with typical defects was established to simulate the process of immersion ultrasonic phased array testing and collect the testing data;Finally,the frequency-domain synthetic aperture imaging is performed based on the phase shift principle.The research results show that the use of ultrasonic phased-array focused scan data for dual-media frequency-domain synthetic aperture imaging,compared with phased-array conventional B-scan imaging,in addition to detecting micro-aperture defects of 0.2 mm in diameter that cannot be imaged by conventional imaging methods,the contrast ratio is improved by an average of 6.39 dB,and the defect localization accuracy is within 1.3%,and the method can provide water immersion ultrasonic phased-array detection of diffusion welding defects in titanium alloys theoretical guidance.