Specimens of the 7N01 aluminum alloy with different grain sizes were prepared by means of heat treatment in this paper in order to analysis the grain size qualitatively.The stress constant K of the specimens after heat treatment was calibrated by uniaxial tensile calibration test.The results showed that the stress constant K increased with the material grain size increasing.The author built the ultrasonic testing platform in this paper.The nominal t0 of the specimens was get based on the cross correlation calculation between reference waveform and capture waveform.The material t0 was also positively associated with the grain size.The relationships between K,t0 and voltage attenuation were established in this paper.Then,the constitutive equation of K,t0 and voltage attenuation was fitted.Therefore,the modified model between the attenuation of LCR wave and the propagation time was established in this paper,and the change of K and t0 were represented by the voltage amplitude.%对7N01铝合金母材进行热处理,制备具有不同晶粒度的试样,定性分析其晶粒度.通过单轴拉伸标定实验测试热处理试样的应力常数K,发现材料的晶粒度越大,应力常数K越大.自行搭建超声波测试平台,基于基准波形和采集波形进行互相关计算,得到各个晶粒度试样的相对t0,发现材料的t0与晶粒度也成正相关关系.使用电压幅值表征材料的声衰减后,建立超声衰减与应力常数K、t0之间的关系,拟合得到超声衰减与K、t0的本构方程.建立关于临界折射纵波衰减度和传播时间的修正模型,使用电压幅值表征K、t0的变化.
展开▼
