利用图像点扩散函数(PSF)近似计算法建立线阵探测器工业CT金属材料X射线衰减测量模型, 并利用该测量模型对垂直于X射线平面边界灰度幅值进行数值计算, 获得当前PSF曲线。在此基础上, 建立基于近似PSF曲线的缺陷检测理论模型, 并对缺陷进行定量检测分析。采用高能6 MeV工业CT线阵探测器系统, 对含有人工缺陷的不锈钢试块进行缺陷检测试验。结果表明: 相比于传统半高宽缺陷测量方法, 本实验方法在缺陷定量检测精度上有较大提高, 从而为提升金属材料内部缺陷的定量检测水平提供新的方法和技术途径。

The model of CT measurement for X-ray attenuation in metallic materials was established by using image Point Spread function(PSF) approximation, the numerical calculation on the gray scale amplitude perpendicular to the X-ray plane boundary was conducted by the measurement model, and the PSF curve was drawn. On this basis, the defects’ quantitative evaluation model was presented according to the PSF curve for defects quantitative evaluation. The stainless steel sample containing artificial defects was analyzed by using the high-energy 6MeV industrial CT linear array detector system. The result shows that, compared with the traditional half-width defects measuring method, this method improves the accuracy of defects quantitative evaluation. This method provides a new and effective tool for high performance of quantitative evaluation on the defects in metallic materials.