一种复杂结构件圆柱面扩散焊缝阵列超声检测方法

Ultrasonic Array Detection Method on Cylindrical Surface Diffusion Weld of Complex Structural Parts

航空发动机某高温合金盘构件采用盘体与叶片环进行焊接的方式制备,由于构件结构复杂,在检测圆柱形焊接面缺陷时,采用单晶超声检测换能器检测效率不高,缺陷信号信噪比低。为提高该种结构件的检测能力,研究圆柱面焊缝的阵列超声自动检测方法,分析面积型缺陷和声源的相对位置对缺陷反射声压和波型转换的影响,提出一种基于双阵列换能器的一发一收检测方案。根据高温合金盘结构设计基于双阵列换能器的声束发射-接收方法和圆柱面焊缝全覆盖检测方案;基于时域有限差分方法建立高温合金盘的阵列超声声学响应仿真模型,对检测参数进行设计和优化。对含有人工缺陷的实际试样进行检测试验,结果表明所提出的双阵列超声换能器检测方法能有效检测到圆柱面焊缝区域?2 mm的当量缺陷。

A superalloy disc component of aeroengine is fabricated by welding between disc and blade ring.Because of the complexity of component structure,the single element ultrasonic testing method has met same problems such as low detection efficiency and low signal-to-noise ratio of defect signals.In order to improve the detection ability of this kind of structure,the automatic ultrasonic array detection method of the cylindrical weld is studied.Firstly,the effect of relative positions of the planar defect and the acoustic source on the defect refection acoustic pressure is analyzed.The wave conversion conditions of different reflected acoustic waves are analyzed and the pitch and catch method based on dual ultrasonic array transducers is put forward.Then,according to the structural characteristic s of the specimen,an acoustic beam transmitting-receiving method and a full coverage inspection scheme for the cylindrical weld are designed.A response simulation model of the ultrasonic array is established based on the finite-difference time-domain(FDTD)method and the detection parameters are designed and optimized.Finally,the detection experiment is carried out on the actual specimen with prefabricated defects,and the results show that the proposed dual ultrasonic array transducer detection method can effectively detect the prefabricated defects with diameter of 2 mm in the cylindrical weld area.