非线性超声对不同塑性变形量铝合金的检测研究
Study on Non-Linear Ultrasonic Testing of Aluminum Alloy with Different Plastic Deformation

在拉伸载荷下对6082-T6铝合金预制不同程度的塑性损伤量，并对各试样进行了非线性超声检测，研究了6082-T6铝合金相对非线性系数β'与残余塑性变形量R_p之间的变化关系；利用XRD-WH方法，对不同塑性损伤试样的位错密度进行了估算，探讨了位错演化和非线性系数的关系。结果表明：在非线性超声检测中，随着塑性损伤的加剧，非线性系数β'首先增长相对缓慢，随后显著增加；随着塑性损伤程度的加剧，位错密度逐渐增加，加强了非线性响应，使相对非线性系数β' 增加。
The plastic damage amount of 6082-T6 aluminum alloy prefabricated in different degrees was studied under tensile load, and the nonlinear ultrasonic test was carried out on each sample. The change relationship between the relative nonlinear coefficient of 6082-T6 aluminum alloy and the residual plastic deformation amount R_p was studied. By means of XRD-WH method, the dislocation density of samples with different plastic damage was estimated, and the relationship between dis-location evolution and nonlinear coefficient was discussed. The results show that: in the nonlinear ultrasonic testing, the nonlinear coefficient increased slowly in the first place with the increase of plastic damage, and then increased significantly. With the increase of plastic damage, the dislocation density increases gradually, which strengthens the nonlinear response and makes the relative nonlinear coefficient increase.