Effects of magnification and sampling resolution in X-ray computed tomography for the measurement of additively manufactured metal surfaces
Effects of magnification and sampling resolution in X-ray computed tomography for the measurement of additively manufactured metal surfaces
复制标题
X 射线计算机断层扫描中放大率和采样分辨率对增材制造金属表面测量的影响
DOI：
10.1016/j.precisioneng.2018.02.014
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
R. Leach
中科院分区：
文献类型：
--
作者：
A. Thompson;N. Senin;I. Maskery;R. Leach
最近的研究表明，X射线计算机断层扫描（XCT）可用于测量增材制造零件的表面形貌。然而，进一步的研究是必要的，以充分了解XCT测量性能。在这里，我们展示了如何放大的X射线投影和分辨率的体积重建网格的影响，在XCT数据处理管道的表面形貌的确定。我们还比较了XCT结果的相干扫描干涉（CSI）测量，并发现，通过增加放大倍数的X射线投影，较小的地形细节可以解决，接近CSI的横向分辨率。结果表明，有一个最佳的设置放大倍率，低于和高于XCT测量性能可以降低。体积重建网格的分辨率的影响不太明显，但通常，采用高于或低于默认值的分辨率会导致曲面确定的可重复性降低。将XCT表面测量的灵敏度确定为设置参数的函数的问题是复杂的，并且还不可能提供无论对象几何形状如何都工作的最佳设置配置。然而，这里提出的方法，以及获得的结果，代表了一个有用的贡献，良好的实践XCT测量表面。
Recent studies have shown that X-ray computed tomography (XCT) can be used to measure the surface topography of additively manufactured parts. However, further research is necessary to fully understand XCT measurement performance. Here, we show how magnification of the X-ray projections and resolution of the volumetric reconstruction grid influence the determination of surface topography in the XCT data processing pipeline. We also compare XCT results to coherence scanning interferometry (CSI) measurements and find that by increasing the magnification of the X-ray projections, smaller topographic detail can be resolved, approaching the lateral resolution of CSI. Results show that there is an optimum setting for magnification, below and above which XCT measurement performance can degrade. The resolution of the volumetric reconstruction grid has a less pronounced effect, but in general, adopting higher or lower resolutions than the default leads to degraded repeatability in surface determination. The problem of determining sensitivity of XCT surface measurement as a function of setup parameters is complex, and it is not yet possible to provide optimal setup configurations that work regardless of object geometry. However, the methods presented here, as well as the results obtained, represent a useful contribution to good practice for XCT measurement of surfaces.