Wire Arc Additive Manufacturing is a near-net-shape processing technology which allows cost-effective manufacturing of large and customized metal parts. Processing of aluminium in Wire Arc Additive Manufacturing is quite challenging, especially in terms of porosity. In the present work, pore behaviour in Wire Arc Additive Manufacturing of AW4043/AlSi5(wt.%) was investigated and a post-process monitoring approach was developed. It has been observed that as the shielding gas flow rate increases, the porosity in aluminium parts also increases due to the rapid solidification of the melt pool by forced convection. The higher convection rate seems to limit the escape of gas inclusions. Furthermore, gas inclusions escaping from the melt pool leave cavities on the surface of each deposited layer. Process camera imaging is used to monitor these cavities to acquire information about the porosity in the part. The observations were supported by Computational Fluid Dynamics simulations which show that the gas flow rate correlates with the porosity in aluminium parts manufactured by Wire Arc Additive Manufacturing. Since a lower gas flow rate leads to reduced convective cooling, the melt pool remains liquid for a longer period allowing pores to escape for a longer period and thus reducing porosity. Based on these investigations, a monitoring approach is presented.

电弧焊增材制造是一种近净形加工技术，可以经济高效地制造大型定制金属零件。线电弧增材制造中的铝加工非常具有挑战性，特别是在孔隙率方面。在目前的工作中，研究了AW4043 / AlSi5（wt。％）的电弧增材制造中的孔隙行为，并开发了一种后处理监测方法。已经观察到，随着保护气体流速的增加，由于强制对流的熔池的快速固化，铝部件中的孔隙率也增加了。较高的对流速率似乎限制了气体夹杂物的逸出。此外，从熔池中逸出的气体夹杂物在每个沉积层的表面上留下空腔。使用过程相机成像来监视这些型腔，以获取有关零件中孔隙率的信息。这些观察得到计算流体动力学仿真的支持，该仿真表明气体流速与由Wire Arc Additive Manufacturing制造的铝制零件中的孔隙率相关。由于较低的气体流速会导致对流冷却降低，因此熔池会长时间保持液体状态，从而使孔逸出更长的时间，从而降低孔隙率。基于这些调查，提出了一种监视方法。由于较低的气体流速会导致对流冷却降低，因此熔池会长时间保持液体状态，从而使孔逸出更长的时间，从而降低孔隙率。基于这些调查，提出了一种监视方法。由于较低的气体流速会导致对流冷却降低，因此熔池会长时间保持液体状态，从而使孔逸出更长的时间，从而降低孔隙率。基于这些调查，提出了一种监视方法。