ABSTRACT Conformal cooling channels, made by the laser powder bed fusion process, are a promising design strategy for optimising cooling and process control of manufacturing tools and injections moulds. The addition of internal features such as corrugations and ribs are becoming an interesting addition to the cooling channel designs. Internal surfaces of laser powder bed fusion components have an inherent process-induced roughness. The roughness may affect the flow in the channels and may affect the addition of internal features by changing the actual geometry of the channels. This work seeks to characterise the variation of the internal surface roughness along the length of seven straight channels, manufactured using the laser powder bed fusion process, by utilising X-ray CT and image analysis. The characterisation showed that the surface roughness varied discontinuously along the length of the channels and that the roughness magnitudes and roughness variations along the channel lengths were dependent on the orientation of the channels with respect to the build direction. Therefore, the actual geometries of multiple, nominally equal, embedded internal features would vary differently from nominal design, dependent on the location of the feature along the channel length and orientation in the channel.

中文翻译：

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研究沿 LPBF 制造的直通道长度的粗糙度变化

摘要 由激光粉末床熔融工艺制成的随形冷却通道是优化制造工具和注塑模具的冷却和工艺控制的一种很有前景的设计策略。添加波纹和肋条等内部特征正成为冷却通道设计的有趣补充。激光粉末床融合部件的内表面具有固有的工艺引起的粗糙度。粗糙度可能会影响通道中的流动，并且可能会通过改变通道的实际几何形状来影响内部特征的添加。这项工作旨在通过利用 X 射线 CT 和图像分析来表征内部表面粗糙度沿七个直通道长度的变化，这些通道是使用激光粉末床融合工艺制造的。表征表明，表面粗糙度沿通道长度不连续变化，并且沿通道长度的粗糙度大小和粗糙度变化取决于通道相对于构建方向的取向。因此，多个名义上相等的嵌入式内部特征的实际几何形状将与名义设计不同，这取决于特征沿通道长度的位置和通道中的方向。