多层介质钛合金梯度材料的阵列超声全聚焦成像方法研究  

Research on Ultrasonic Array Total Focusing Imaging Method of Titanium Alloy Gradient Material with Multi-Layer Medium

作　　者：李文涛[1] 张文宾 王俊 周正干[2] LI Wentao;ZHANG Wenbin;WANG Jun;ZHOU Zhenggan(School of Mechanical and Electronical Engineering,Lanzhou University of Technology,Lanzhou 730050;School of Mechanical Engineering and Automation,Beihang University,Beijing 100083)

机构地区：[1]兰州理工大学机电工程学院,兰州730050 [2]北京航空航天大学机械工程及自动化学院,北京100083

出　　处：《机械工程学报》2024年第14期69-76,共8页Journal of Mechanical Engineering

摘　　要：增材制造钛合金梯度材料在航空航天、武器装备的系统性能提升和结构减重等方面具有重要应用价值。针对梯度材料多层介质不均匀性导致的检测信噪比低,阵列超声聚焦成像算法设计和校正困难等问题,通过分析超声波在多介质层内部的传播特性,给出各介质层界面的反射系数和透射系数和衰减系数的计算公式,建立合成声束在其内部的聚焦声场分布模型,基于一种比例常数提出了多层介质中阵列超声传播路径的快速计算方法。针对采用增材制造技术制备的TA15-Ti2AlNb梯度材料试件建立了全聚焦(Total focusing method,TFM)校正成像算法,采用线阵和环阵换能器的试验结果均表明该方法能有效提高梯度材料内部缺陷的检测信噪比和定量精度。Gradient materials of additive manufacturing titanium alloy have important application value in aerospace,weapon system performance improvement and structural weight reduction.Aiming at the problems of low signal-to-noise ratio(SNR)and difficulty in calculation and correction of focusing imaging algorithm caused by the inhomogeneity of multi-layer medium of gradient materials.By analyzing the propagation characteristics of ultrasonic wave in multi-layer medium,the formulas for calculating the reflection and transmission coefficient of each interface are given.The focusing acoustic field distribution model of the synthetic beam is established,and a fast calculation method for the propagation path of the ultrasonic array beam in multi-layer medium is proposed.A correction imaging algorithms of total focusing method(TFM)is established for the TA15-Ti2AlNb gradient material specimen prepared by additive manufacturing technology,the experimental results using linear array and annular array transducers show that this method can effectively improve the SNR and quantitative accuracy of internal defects in the gradient material.

关 键 词：阵列超声 多层介质 梯度材料 全聚焦成像 传播特性 

分 类 号：TB553[理学—物理]