The techniques we now know as 3D printing or additive manufacturing were once only used for prototyping – producing physical models that were just a representation of a design concept. Now, they are firmly established as ways to make finished parts – thanks to the advent of better materials and more accurate control of part production.
3D printing first started to be used as a production technique, for parts in the motorsports and aerospace industry. Now, sophisticated techniques such as DMLS (direct metal laser sintering) can be used to make highly engineered metal parts.
In DMLS, powdered metals and alloys are ‘cured’ using powerful lasers – to create finished parts in materials including aluminium, stainless steel and even titanium. The technique can be used to make detailed designs in a short timeframe. Examples of the kinds of parts that can be made using DMLS include heat exchangers, surgical tools and pump components. Techniques such as DMLS are becoming increasingly popular in the aerospace industry, for instance, where volumes of specialised parts can be quite low.
Techniques such as DMLS are not intended as direct replacements for established techniques such as casting or CNC machining. Instead, they are chosen for small production runs. Aerospace, automotive and medical companies have all found that 3D printing is a more appropriate technique for making certain low volume but high-quality parts. The production volume for which a technique such as DMLS is more economically viable than, say, CNC machining, will change depending on exact conditions.
Another critical difference is that DMLS, as an additive manufacturing technique, can be used to make parts that would be near-impossible to produce using more traditional methods. The kinds of ‘organic’ shape possible using DMLS would make no sense when using, say, CNC machining. However, these designs can offer important advantages, such as improved aerodynamics and lighter weight.
Some people still consider 3D printing as a prototyping technique, to make demonstration models for clients. However, the increasing sophistication of techniques like DMLS means they can be used to make advanced parts for demanding industries such as aerospace. When used selectively, 3D printing can be the technique of choice for the production of low volume parts