Predictive process parameter selection for Selective Laser Melting Manufacturing: Applications to high thermal conductivity alloys
Predictive process parameter selection for Selective Laser Melting Manufacturing: Applications to high thermal conductivity alloys
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DOI：
10.1016/j.addma.2018.12.003
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发表时间：
2019-05-01
影响因子：
11
通讯作者：
Jaegle, Eric A.
中科院分区：
文献类型：
--
作者：
Bajaj, Priyanshu;Wright, Jonathan;Jaegle, Eric A.
人们对高导电性金属（例如铜和难熔金属）的激光粉末床熔融（L-PBF）或选择性激光熔化（SLM）制造越来越感兴趣。高导热率金属的SLM制造特别困难。在难熔金属的情况下，由于其高熔点和脆性行为，困难被放大。快速工艺开发策略对于确定合适的工艺参数以在这些合金中实现最小孔隙率是必不可少的，然而当前策略受到若干限制。我们提出了一个简单的方法，快速开发过程中使用规范化的过程地图。使用归一化能量密度与归一化阴影间距的图，我们确定了宽的加工窗口。这是进一步完善使用分析传热模型来预测熔池尺寸。最后的参数优化是通过基于统计实验设计概念的实验来实现的。在这篇文章中，我们展示了使用我们提出的方法来开发的工艺参数（舱口间距，层厚度，曝光时间和点距离）SLM制造钼和铝。对于钼和铝，分别使用200 W脉冲激光和400 W连续激光实现了97.4%和99.7%的相对密度，证明了我们的方法用于SLM加工高导电性材料的有效性。
There is growing interest in Laser Powder Bed Fusion (L-PBF) or Selective Laser Melting (SLM) manufacturing of high conductivity metals such as copper and refractory metals. SLM manufacturing of high thermal conductivity metals is particularly difficult. In case of refractory metals, the difficulty is amplified because of their high melting point and brittle behaviour. Rapid process development strategies are essential to identify suitable process parameters for achieving minimum porosities in these alloys, yet current strategies suffer from several limitations. We propose a simple approach for rapid process development using normalized process maps. Using plots of normalized energy density vs. normalized hatch spacing, we identify a wide processability window. This is further refined using analytical heat transfer models to predict melt pool size. Final optimization of the parameters is achieved by experiments based on statistical Design of Experiments concepts. In this article we demonstrate the use of our proposed approach for development of process parameters (hatch spacing, layer thickness, exposure time and point distance) for SLM manufacturing of molybdenum and aluminium. Relative densities of 97.4% and 99.7% are achieved using 200 W pulsed laser and 400 W continuous laser respectively, for molybdenum and aluminium, demonstrating the effectiveness of our approach for SLM processing of high conductivity materials.