熔覆层厚度对相控阵表面波聚焦特性的影响  

The Influence of Cladding Layer Thickness on Surface Wave Focusing Characteristics of Phased Array

作　　者：周永立 周刚 胡宏伟[1] 刘芝平 ZHOU Yongli;ZHOU Gang;HU Hongwei;LIU Zhiping(School of Automotive and Mechanical Engineering, Changsha University of Science and Technology,Changsha 410114,China)

机构地区：[1]长沙理工大学汽车与机械工程学院,湖南长沙410114

出　　处：《压电与声光》2020年第6期752-756,760,共6页Piezoelectrics & Acoustooptics

基　　金：国家自然科学基金资助项目(52075049);湖南省自然科学杰出青年基金资助项目(2020JJ2028);湖南省教育厅科学研究重点基金资助项目(18A142)。

摘　　要：超声表面波是检测激光熔覆层质量的重要手段,为提高检测分辨率,采用可达到声束聚焦效果的相控阵表面波对激光熔覆层进行检测。建立了单探头与相控阵表面波传播的有限元模型,基于Fermat原理研究超声波传播路径并分析了阵元延时特性,实现了相控阵表面波的聚焦和偏转,研究了熔覆层厚度对相控阵表面波聚焦特性的影响。结果表明,对于基体材料为铝,熔覆层材料为45#钢时,熔覆层厚度在2.5 mm内,聚焦点的能量随厚度增加而减小,如1 mm厚相对于0.2 mm厚的聚焦点能量减小了58.8%;当厚度大于2 mm时,聚焦点处能量变化不明显,表明超声相控阵表面波对薄的熔覆层具有较好的检测效果。The ultrasonic surface wave is an important method to detect the quality of laser cladding layer.In order to improve the detection resolution,the phased array surface wave which can achieve the focusing effect of acoustic beam is used to detect laser cladding layer.Firstly the finite element model of surface wave propagation between single probe and phased array is established.Subsequently,the ultrasonic wave propagation path is studied based on the Fermat principle and the delay characteristics of the array elements.The focusing and deflection of the phased array surface wave are realized,and the influence of the thickness of the cladding layer on the focusing characteristics of the phased array surface wave is studied.The results show that when the base material is aluminum and the cladding layer material is 45#steel,the thickness of the cladding layer is within 2.5 mm,and the energy of the focal point decreases with the increase of thickness.Especially,the energy of the focal point decreases by 58.8%with the thickness of 1 mm compared to 0.2 mm.When the thickness is greater than 2 mm,the energy changes little at the focus point,indicating that the ultrasonic phased array surface wave has a good detection effect on the thin cladding layer.

关 键 词：超声相控阵 表面波 激光熔覆层 聚焦特性 有限元 

分 类 号：TN65[电子电信—电路与系统] TB553[理学—物理]