增材制造流道多余物X射线成像检出能力研究

X-ray Imaging Detection Capability of Residues in Additive Manufactured Channels

采用激光选区熔化工艺增材制造了含复杂流道的燃烧室模拟件,流道内部预制了不同尺寸的凸出立方体多余物,并放置一组标准尺寸金属丝模拟线形多余物。采用计算机射线照相(Computed radiology,CR)和显微计算机层析成像(Computed tomography,CT)对试样进行检测,研究X射线成像方法对增材制件内部流道多余物的检测能力,并采用显微CT对流道壁厚进行分析与评估。结果表明,CR可检出最小设计尺寸为0.15 mm的凸出立方体多余物和最小丝径为0.1 mm的线形多余物;显微CT可检出最小设计尺寸为0.08 mm的凸出立方体多余物和最小丝径为0.1 mm的线形多余物。显微CT尺寸测量结果显示,线形多余物测量尺寸与标准尺寸一致,凸出立方体多余物测量尺寸普遍大于设计尺寸,最大绝对误差不超过50μm。通过显微CT壁厚分析发现,宽段流道均匀性良好。

A combustion chamber simulator with complex channels was manufactured by selective laser melting technique.Convex cubic residues with different sizes were prefabricated in the channels,and a set of standard size metal wires were placed to simulate linear residues.Computed radiology(CR)and microscopic computed tomography(CT)were utilized to investigate the detection capability of X-ray imaging method for residues in the internal channels of additive parts,and the wall thickness of channel was analyzed and evaluated by micro-CT.The results indicate that CR can detect the convex cubic residues with a minimum size of 0.15 mm and linear residues with a minimum diameter of 0.1 mm,while micro-CT can detect the convex cubic residues with a minimum size of 0.08 mm and linear residues with a minimum diameter of 0.1 mm.The measurement sizes of linear residues are consistent with standard size,while that of convex cubic residues are generally larger than the designed sizes with the maximum absolute error less than 50μm.Moreover,the wide-section channels exhibit desirable uniformity by micro-CT.