Direct metal laser sintering (DMLS) is the leading additive method for making metal prototypes. It is similar to selective laser sintering of plastic resin, but is suitable for use with metals including aluminium, stainless steel, titanium, cobalt chrome and Inconel. It offers good accuracy and detail, and excellent mechanical properties. DMLS can be used for very small parts and features, and because it is an additive process, it can reproduce geometries that might be impossible to machine such as enclosed spaces. Layers can be as thin as 20 microns, and tolerances on small features can be as small as ±0.002 inches. Secondary operations on parts produced by DMLS can include machined drilling, slotting, milling and reaming, and finishing procedures including anodising, electro-polishing, hand polishing, and powder coating or painting.
- Capable of working with nearly any alloy
- Mechanical properties parts equal to conventionally formed parts
- Can make geometries that are impossible to machine or cast
- Relatively slow
- Requires expertise to make quality parts
- Usually requires expensive post-processing
- Unwanted volume – build volume – material to be solidified + number of layers dictates the time and cost. Not the complexity of the part
- external corners to be round rather than sharp
- Overall, the most ideal geometries are small, self-supporting parts that would be difficult to manufacture through machining, are too expensive to investment cast, or are metal parts requiring short lead times.