Powder recycling is accepted as a key commercial advantage in Selective Laser Melting technology. Yet, surprisingly, little to no information is publicly available on this topic. So what’s the catch?
Selective laser melting (SLM) is used to manufacture a patient-specific stainless steel positioning guide for spinal screws. The screws are successfully inserted in the neck vertebrae of a 3-year old patient to strengthen unstable joints. This article highlights the challenges and describes the steps used to design, customise, build and post-process the component.
May arise from powder surface chemistry modification and/or trapped gas in particles that are released during melting and locked in during solidification
May also be due to key-hole effect for deep melt pools.
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.
Among metal additive manufacturing processes, Selective Laser Melting (SLM) belongs to the powder bed fusion category. Also known as Direct Metal Laser Melting (DMLM), the technique is named after its fundamental mechanism. The process relies on a fine laser beam that is scanned across successive layers of a powder bed to selectively melt intricate tracks. The final components arise from solidification of the melted powder. When compared to other additive manufacturing technologies, this ability to produce high resolution features is one of the reasons why SLM tends to get selected to produce complex components with delicate features.
How do you combine design guiderules for SLM and topology optimisation? How do you prioritise the design optimisation tasks while minimising the design iterations?
Industrial designers do not yet have a clear framework to review, redesign, and optimise existing designs in order to take full advantage of the benefits that SLM can offer.
In this post, we present the methodology used to redesign an aluminium bracket for SLM in order to save weight while maintaining performance. The key objective is to take into account the manufacturing constraints, user’s requirements and take advantage of technology’s design freedom.
Effect of particles size distribution and packing density on the formation of balling defects during SLM of In718
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.