铝合金塑性损伤电磁超声谐振无损评估研究

Study on Electromagnetic Acoustic Resonance Nondestructive Evaluation of Aluminum Alloy Plastic Damage

针对传统线性超声方法难以有效检测金属构件微损伤的问题,使用电磁超声换能器,在6061铝合金试件内发射并接收超声信号,采用非线性电磁超声谐振方法对铝合金试件拉伸时产生的塑性损伤进行无损评估。基于非线性电磁超声谐振检测实验平台,对不同拉伸阶段的试件分别进行了非线性检测实验,通过基波与三次谐波的幅值比,定量地描述了铝合金材料的非线性参数与材料拉伸损伤程度相关关系。实验结果表明:弹性阶段的拉伸处理对试件的非线性情况影响较小,而塑性阶段的拉伸造成的微损伤对试件的非线性情况有较大影响,因此非线性电磁超声谐振技术可以有效评估铝合金塑性损伤。

Aiming at the problem that the traditional linear ultrasonic method was difficult to effectively detect the micro damage of metal components,the nonlinear electromagnetic ultrasonic resonance method was used to non-destructively evaluate the plastic damage generated during the stretching of aluminum alloy specimens by using an electromagnetic acoustic transducer to excite and receive ultrasonic signals inside 6061 aluminum alloy specimens.Based on the nonlinear electromagnetic acoustic resonance testing experimental platform,the nonlinear testing experiments were carried out for specimens in different tensile stages,and the correlation between the nonlinear parameters and the degree of material tensile damage was quantitatively described by the amplitude ratio of fundamental wave to third harmonic wave.The experiment results show that the tensile process in the elastic stage has less influence on the nonlinear condition of the specimen,while the micro damage caused by the tensile stage in the plastic stage has a greater influence on the nonlinear condition of the specimen,so the nonlinear electromagnetic ultrasonic resonance technique can effectively evaluate the plastic damage of aluminum alloy.