Purpose

Conformal cooling channels in additively manufactured molds are superior over conventional channels in terms of cooling control, part warpage and lead time. The heat transfer ability of cooling channels is determined by their geometry and surface roughness. Laser powder bed fusion manufactured channels have an inherent process-induced dross formation that may significantly alter the actual shape of nominal channels. Therefore, it is crucial to be able to predict the expected surface roughness and changes in the geometry of metal additively manufactured conformal cooling channels. The purpose of this paper is to present a new methodology for predicting the realistic design of laser powder bed fusion channels.

Design/methodology/approach

This study proposes a methodology for making nominal channel design more realistic by the implementation of roughness prediction models. The models are used for altering the nominal shape of a channel to its predicted shape by point cloud analysis and manipulation.

Findings

A straight channel is investigated as a simple case study and validated against X-ray computed tomography measurements. The modified channel geometry is reconstructed and meshed, resulting in a predicted, more realistic version of the nominal geometry. The methodology is successfully tested on a torus shape and a simple conformal cooling channel design. Finally, the methodology is validated through a cooling test experiment and comparison with simulations.

Practical implications

Accurate prediction of channel surface roughness and geometry would lead toward more accurate modeling of cooling performance.

Originality/value

A robust start to finish method for realistic geometrical prediction of metal additive manufacturing cooling channels has yet to be proposed. The current study seeks to fill the gap.

中文翻译：

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激光粉末床融合通道的现实设计

目的

在冷却控制，零件翘曲和交货时间方面，增材制造模具中的保形冷却通道优于传统通道。冷却通道的传热能力取决于其几何形状和表面粗糙度。激光粉末床熔合制造的通道具有固有的过程引起的渣formation形成，可能会显着改变名义通道的实际形状。因此，至关重要的是能够预测预期的表面粗糙度和金属增材制造的共形冷却通道的几何形状变化。本文的目的是提供一种预测激光粉末床融合通道实际设计的新方法。

设计/方法/方法

这项研究提出了一种通过实施粗糙度预测模型使标称通道设计更加现实的方法。这些模型用于通过点云分析和操纵将通道的标称形状更改为其预测形状。

发现

作为一个简单的案例研究，对直通道进行了研究，并针对X射线计算机断层扫描测量进行了验证。修改后的通道几何形状将被重建并划分网格，从而产生名义几何形状的预测，更实际的版本。该方法已在圆环形状和简单的共形冷却通道设计上成功进行了测试。最后，通过冷却测试实验并与模拟进行比较来验证该方法。

实际影响

通道表面粗糙度和几何形状的准确预测将导致更精确的冷却性能建模。

创意/价值

尚未提出用于金属增材制造冷却通道的实际几何预测的可靠的开始到完成方法。当前的研究试图填补空白。