Areal topography measurement of metal additive surfaces using focus variation microscopy
Areal topography measurement of metal additive surfaces using focus variation microscopy
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DOI：
10.1016/j.addma.2018.11.013
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发表时间：
2019-01-01
影响因子：
11
通讯作者：
Leach, Richard
中科院分区：
文献类型：
--
作者：
Newton, Lewis;Senin, Nicola;Leach, Richard
本文研究了一种用于金属添加剂表面形貌测量的变焦距测量仪的性能。使用激光和电子束粉末床熔融工艺与一些最常见的添加剂材料：Al-Si-10 Mg、Inconel 718和Ti-6Al-4V生产样品。研究了平行于和正交于构建方向的表面。通过目视检查从测量获得的地形模型，并通过计算非测量数据点的数量，通过估计地形高度确定中的局部重复性误差和通过计算面积场纹理参数Sa的值来量化测量性能。通过这些指标捕获的变化进行了研究，因为焦点变化特定的测量控制参数是不同的。研究了放大率、照明类型、垂直分辨率和横向分辨率的变化。通过全因子实验设计创建实验活动，并使用回归模型将选定的测量过程控制参数与测量的性能指标联系起来。结果表明，聚焦变化显微镜测量金属添加剂表面是强大的测量控制参数的变化时，Sa纹理参数被认为是，与变化局限于亚微米尺度和相同的表面和目标的平均参数值的5%以内。测量控制参数的选择对非测点个数和局部重复性误差影响较大。然而，这种变化可以预测的回归模型，并证明一致的材料，类型的添加剂过程和测量表面的方向设置。
In this work, the performance of a focus variation instrument for measurement of areal topography of metal additive surfaces was investigated. Samples were produced using both laser and electron beam powder bed fusion processes with some of the most common additive materials: Al-Si-10Mg, Inconel 718 and Ti-6Al-4V. Surfaces parallel and orthogonal to the build direction were investigated. Measurement performance was qualified by visually inspecting the topographic models obtained from measurement and quantified by computing the number of non-measured data points, by estimating local repeatability error in topography height determination and by computing the value of the areal field texture parameter Sa. Variations captured through such indicators were investigated as focus variation-specific measurement control parameters were varied. Changes in magnification, illumination type, vertical resolution and lateral resolution were investigated. The experimental campaign was created through full factorial design of experiments, and regression models were used to link the selected measurement process control parameters to the measured performance indicators. The results indicate that focus variation microscopy measurement of metal additive surfaces is robust to changes of the measurement control parameters when the Sa texture parameter is considered, with variations confined to sub-micrometre scales and within 5% of the average parameter value for the same surface and objective. The number of non-measured points and the local repeatability error were more affected by the choice of measurement control parameters. However, such changes could be predicted by the regression models, and proved consistent once material, type of additive process and orientation of the measured surface are set.