增材制造小缺陷的显微CT检测

Micro-CT detection of small defects in additive manufacturing

通过高精度金属增材制造技术设计制造了两组不同类型的缺陷试件,并基于显微CT检测技术和缺陷解剖金相检测方式,研究显微CT对增材制造小缺陷的实际检测能力。试验结果表明,显微CT在体素尺寸5μm下能有效检出尺寸为20μm的人工缺陷;金相检测与CT检测结果基本一致,缺陷尺寸测量差小于10μm;由于部分体积效应的影响,更小尺寸缺陷的尺寸测量结果误差更大。

In this paper,two groups of different types of defective specimens were designed and manufactured through high-precision metal additive manufacturing technology.Based on the micro-CT detection technology and the defect anatomical metallographic detection method,the actual detection ability of micro-CT on small defects of additive manufacturing was studied.The research results showed that micro-CT can effectively detect the artificial defects of 20μm under the voxel size of 5μm;metallographic detection and CT detection results were basically the same,and the difference in the measurement of the defect size was less than 10μm;the defects of smaller sizes were more inaccurate due to the influence of the partial volume effect of the dimensional measurement results.