Selective laser melting (SLM)

Selective laser Melting (SLM)

Selective Laser Melting is an additive manufacturing process that enables the production of metal parts using high-power lasers. These lasers fuse metal powder particles gradually and locally, in a full melting process and a controlled atmosphere.
This technology allows the manufacture of functional components with high structural integrity at a low cost. It is compatible with various materials, including biocompatible titanium alloys.
SLM is very similar to SLS, and both processes are covered under the powder bed fusion umbrella. The significant difference between both processes is the type of feedstock or powder required. While SLS mainly relies on nylon (PA) polymer materials, SLM is specially designed for metals. Besides, SLM technology leverages various metal powders including titanium, cobalt-chromium, steel, stainless steel, copper or aluminium, to name a few of them.
Furthermore, with SLM, a high-power fiber laser scans the powder surface. Thereafter, the generated heat melts the powder particles and creates a molten pool. Once the layer is scanned, the platform drops down by a single-layer thickness in the z-axis, and the fresh layer of powder is deposited. The process is repeated until the end of the entire part. Loose powders are removed once the full component is produced.
SLM parts must be fabricated in an inert gas atmosphere such as argon to remove oxygen from the building chamber. The substrate is removed from the build chamber once the process completes, and the supports are removed carefully.
SLM is one of the AM technologies that is gaining momentum today. The technology enables a wide range of applications for rapid prototyping and mass production. The end parts produced via SLM integrate properties that are similar to those manufactured via traditional manufacturing processes.

Diagram of the selective laser melting (laser sintering) process