A few months ago, we were wondering about process control in powder bed fusion of reactive powders. What are the impacts of particles’ surface contamination on the fabrication of metal components? And what are the best ways to minimise it during the complete manufacturing cycle?
 
Then, very few studies were trying to assess the impact of powder particles surface chemistry on the process (powder spreading, melt wettability, pores formation, etc…) and on the final product characteristics (relative density, etc).
 
As more data get publicly available, we can present the results of a detailed investigation aiming to 1) understand the effects of powder surface chemistry, 2) minimise particles surface contamination on the finished products and 3) improve SLM process control.

Balling is a defect that can occur when the molten pool created during selective laser melting (SLM=L-PBF) becomes discontinuous and breaks into separated islands. In this post, we report and discuss how the powder particle arrangement impact the bead geometry and formation of balling defects during SLM.

Direct Laser Deposition (DLD) is a type of laser-based additive manufacturing process used to create functional metal components layer by layer using a sliced 3D CAD (computer aided drawing) file. Unlike Selective Laser Melting which utilizes a bed of powder metal that is ‘selectively’ melted via a laser, DLD is based on melting feedstock (blown powder or wire) at the focus point of a laser source. In this post, we address the residual stresses occurring during the build of metal components with DLD technology [1].