Laser sintering is hot. Better known by the popular name the media has attached to the overall technology, 3D printing, you can’t look at a news roundup these days without running into a slew of articles on the supposedly “new” industrial process.
But the technology actually has been around for quite a while, going back to the 1980s when the first articles on stereolithography and fused deposition modeling began showing up in technical journals. Advances came quickly in the 1990s with the development of new techniques using different substances – such as thermoplastics, ceramics and metal powders – as the fabrication material for creating rapid prototypes with lasers. By the 2000s, enough progress had been made for the technology to graduate beyond mere prototyping and into the production process itself, where it is now referred to as rapid manufacturing (or additive manufacturing). The two most advanced forms of creating products with the technology now are: select laser sintering (SLS), which uses plastics; and (DMLS), which works with metal powders (see our previous blog entry “Harbec Explains DMLS Technology”). So laser sintering has really come a long way in the last few decades and today is a fairly mature applied science.
Still, there are many misconceptions about DMLS, in particular, that have lingered in the public imagination. To dispel some of these, we offer a brief FAQ on the facts of DMLS.
Q: Some people say that DMLS is only for prototyping and not for real manufacturing. True?
A: DMLS is one of the few additive manufacturing technologies being used in production, especially for limited production (and just-in-time) runs. (Please see the article “Cyclists Take Industrial 3D Printing for a Spin” about one of our clients who used our services to create customized components for his mountain-bike parts.) Obviously, DMLS doesn’t fill the bill for everything. It doesn’t lend itself to all manufacturing as far as cost savings. DMLS excels at highly complex parts that typically would require multiple operations or electric discharge machining; however, simple easily CNC machined parts are usually not cost effective. DMLS has many benefits over traditional manufacturing in general, and chief among these is speed (which leads to reduced costs). DMLS will always turn around parts more quickly.
Q: Is DMLS more expensive than traditional machining or casting?
A: Using a build plate of 250 mm by 250 mm by 325 mm, we can lay out a variety of parts. We can fit numerous parts on this plate, so we can reduce per unit cost in this way. If you were machining these, you would normally make just one part at a time. But we can put as many parts as possible in that volume on the plate to reduce the set up and process costs. The more parts you can put in per build, the less each part will cost.
A: As far as being able to make a series of parts, the metals that we use are 100 percent dense and are able to be machined and welded and can be coated, plated and treated the same as parts machined from a solid billet of material. Plus, they can be hardened. These parts have good mechanical properties, such as strength and durability, that are comparable to cast or forged parts from the same kind of metal.
So there you have the FAQs of the matter, as we see it. For a similar take on the topic, please see the articles “A Short Look at Direct Metal Laser Sintering Technology” and “You’re Wrong: 5 Common Misconceptions about DMLS.” Or contact one of our sales representatives for further information on DMLS manufacturing.