高温合金晶粒尺寸的超声评价方法及检测装置

针对超声声速、衰减系数、非线性系数等特征参数表征GH4169晶粒尺寸存在检测误差较大的问题,以指数函数为映射函数,将多个超声特征参数归一化后融合构造出新的特征参数,建立以平均绝对误差最小为优化目标的优化问题,并结合遗传算法进行求解,从而确定最优超声多参数评价模型,开发实时超声检测与晶粒尺寸评价相结合的检测装置并进行实验验证。结果表明,所构建的超声多参数评价误差小、单调性好;超声检测装置在已知模型的基础上,可对实时采集的超声A扫信号进行特征提取并计算检测位置的平均晶粒尺寸。

Ultrasonic Evaluation Method and Detecting Device for Grain Size of High Temperature Alloy

According to the characteristic parameters of ultrasonic sound velocity, attenuation coefficient and nonlinear coefficient, the detection error of grain size of GH4169 is large. The exponential function is used as the mapping function. The ultrasonic parameters are normalized and then merged to construct new characteristic parameters. The optimization problem with the minimum absolute error is optimized, and the genetic algorithm is used to solve the problem, so as to determine the optimal ultrasonic multi-parameter evaluation model, and develop a real-time ultrasonic detection and grain size evaluation combined detection device and verify the experiment. The results show that the constructed ultrasonic multi-parameter evaluation error is small and monotonous; based on the known model, the ultrasonic detection device can extract the feature of the ultrasonic A-scan signal collected in real time and calculate the average grain size of the detected position.