金属增材制件射线检测缺陷检出概率分析

POD analysis of defect in radiographic testing of metal additive parts

针对增材制造射线检测缺乏缺陷检出概率数据易导致裂纹、孔隙缺陷漏检问题,以GH3625高温合金增材制件的线型缺陷和孔型缺陷为研究对象,使用CIVA2020仿真平台模拟X射线检测并得到缺陷检出概率(POD)曲线,研究两种缺陷不同尺寸变化对缺陷检出概率的影响,确定不同影响因素下缺陷检出尺寸及检出概率,并利用Sgompertz函数拟合得到线型缺陷受深度影响的POD曲线方程以及孔型缺陷受半径影响的POD曲线方程,建立了增材制造线型缺陷和孔型缺陷的缺陷检出概率模型。结果表明:在95%的置信水平下以90%概率可检出的线型缺陷长度尺寸为0.211 mm、宽度尺寸为0.213 mm、深度尺寸为0.178 mm,孔型缺陷可检出的直径尺寸为0.188 mm,高度尺寸为0.190 mm。通过实际试样微焦点射线成像检测以及胶片射线照相检测对仿真结果进行对比验证。表明建立的缺陷检出概率模型较为准确,可为增材制造中裂纹与孔隙缺陷检测可靠性分析提供依据。

In view of vulnerability to cracks and pore defects due to lacking of defect detection probability data in radiographic examination of additive manufacturing,the linear defects and pore defects of GH3625 superalloy additive parts were researched.The CIVA2020 simulation platform was used to simulate X-ray inspection and obtain the probability of detection(POD)curve of defects,research the influence of different size changes of the two types of defects on the POD of defects.The detectable size of defects and POD under different influencing factors were determined,and the POD curve equation of linear defect affected by depth and the POD curve equation of pore defect affected by radius were fitted by Sgompertz function,the defect detection probability model of additive manufacturing line defects and pore defects was established respectively.The detectable length size of linear defects was 0.211 mm,the detectable width size was 0.213 mm,the detectable depth size was 0.178 mm at a probability of 90% under 95% confidence level,the detectable diameter size of pore defects was 0.188 mm,and the detectable height size was 0.190 mm.The simulation results were compared and verified by micro-focus radiography and film radiography of actual specimens.The research results showed that the defect detection probability model is more accurate and can provide a basis for reliability analysis of crack and pore defect detection in additive manufacturing.