A novel cold wire gas metal arc (CW-GMA) process for high productivity additive manufacturing
A novel cold wire gas metal arc (CW-GMA) process for high productivity additive manufacturing
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DOI：
10.1016/j.addma.2023.103681
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发表时间：
2023-07-01
影响因子：
11
通讯作者：
Williams, Stewart
中科院分区：
文献类型：
--
作者：
Wang, Chong;Wang, Jun;Williams, Stewart
线弧定向能量沉积（DED）适合于以高沉积速率沉积大尺寸金属部件。为了通过减少总制造时间来进一步提高生产率和效率，需要更高的沉积速率。然而，以高能量输入为特征的传统的基于气体金属电弧（GMA）的丝弧DED通常导致在相对高的沉积速率下的高重熔和再加热，从而降低了工艺效率并劣化了机械性能。在这项研究中，一种新的电弧DED工艺与GMA和外部冷丝，即冷丝气体金属电弧（CWGMA）的组合，提出了实现高沉积速率和低材料重熔。研究了不同能量输入水平下的最大沉积速率，最高沉积速率达到14 kg/h。使用该工艺以约10 kg/h的高沉积速率构建了重280 kg的工业规模组件，这证明了该工艺用于高生产率应用的能力。还发现，由于冷丝的加入，重熔显著减少。建立了CW-GMA工艺的工作包线和几何过程模型，该模型可用于避免工艺参数选择中的缺陷和预测单程壁结构的几何形状。此外，在CW-GMA工艺中加入冷丝降低了比能量密度，导致晶粒尺寸和各向异性减小，这改善了机械性能，增加了强度并降低了各向异性。
Wire-arc directed energy deposition (DED) is suitable for depositing large-scale metallic components at high deposition rates. In order to further increase productivity and efficiency by reducing overall manufacturing time, higher deposition rates are desired. However, the conventional gas metal arc (GMA) based wire-arc DED, characterised by high energy input, normally results in high remelting and reheating at relatively high deposition rates, reducing the process efficiency and deteriorating the mechanical performance. In this study, a novel wirearc DED process with the combination of a GMA and an external cold wire, namely cold wire-gas metal arc (CWGMA), was proposed for achieving high deposition rate and low material remelting. The maximum deposition rates at different levels of energy input were investigated, with the highest deposition rate of 14 kg/h being achieved. An industrial-scale component weighing 280 kg was built with this process at a high deposition rate of around 10 kg/h, which demonstrated the capability of the process for high productivity application. It was also found that, due to the addition of the cold wire, the remelting was reduced significantly. The working envelope and geometric process model for the CW-GMA process was developed, which can be used to avoid defects in parameter selection and predict the geometry of single-pass wall structures. Moreover, the addition of the cold wire in the CW-GMA process reduced the specific energy density, leading to a reduction in both grain size and anisotropy, which improved the mechanical properties with increased strength and reduced anisotropy.