When you see the term cold fusion, you probably think about energy generation, but the Cold Metal Fusion Alliance is an industry group all about 3D printing metal using Selective Laser Sintering (SLS) printers. The technology promoted by Headmade Materials typically involves using a mix of metal and plastic powder. The resulting part is tougher than you might expect, allowing you to perform mechanical operations on it before it is oven-sintered to remove the plastic.
The key appears to be the patented powder, where each metal particle has a thin polymer coating. The low temperature of the laser in the SLS machine melts the polymer, binding the metal particles together. After printing, a chemical debinding system prepares the part — which takes twelve hours. Then, you need another twelve hours in the oven to get the actual metal part.
You might wonder why we are interested in this. After all, SLS printers are unusual — but not unheard of — in home labs. But we were looking at the latest offerings from Nexa3D and realized that the lasers in their low-end machines are not far from the lasers we have in our shops today. The QLS230, for example, operates at 30 watts. There’s plenty of people reading this that have cutters in that range or beyond out in the garage or basement.
We aren’t sure what a hobby setup would look like for the debinding and the oven steps, but it can’t be that hard. Maybe it is time to look at homebrew SLS printers again. Of course, the powder isn’t cheap and is probably hard to replace. We saw a 20 kg tub of it for the low price of €5,000. On the other hand, that’s a lot of powder, and it looks like whatever doesn’t go into your part can be reused so the price isn’t as bad as it sounds. We’d love to see someone get some of this and try it with a hacked printer.
We have seen homebrew SLS printers. There’s also OpenSLS that, coincidentally, uses a laser cutter. It wouldn’t be cheap or easy, but being able to turn out metal parts in your garage would be quite the payoff. Be sure to keep us posted on your progress.
I’ve been interested in amorphous metals and wonder if the bonding agent using it could be sintered using this tech….it seems a very high price for bare materials…hopefully someone will buy a quantity and sub-divide it into hobbiest levels.
I wonder how the final properties of weight to strength and costs with other processes
Binder jetting is going to be the future in the metal department for the foreseeable hobbyist’s future.
Maybe something else than plastic. Maybe organic.
…and sintering in microwave kiln…
Cold Metal Fusion Alliance is a dumb name, There is no cold fusing of metal here.
All sintering and MANY debinding processes are thermal in nature.
Cold metal fusion alliance should be focused on ultrasonic additive manufacturing, metal foil fusion. At least thats KINDA cold metal fusion.
You can buy 30-50w fiber laser engravers with galvo heads for under $3k on the bay. You cant touch a decent sintering oven for that.
You’re kidding, right?
I just typed “kiln” into eBay and there was only one listing over $3k ($3,200 obo).
thats a kiln. Not a sintering furnace.
A sintering furnace is capable of operating under vacuum or inert gas.
Only a very small selection of alloys can be effectively sintered under normal atmosphere.
NOTE: dental sintering furnaces youll find on ebay are intended for use with zirconia ceramics and do not provide the controlled atmosphere necessary for metal compaction
You can. I’ve found them on Alibaba with vacuum and inert gas environments, 3 phase system under 30 amps for about €3k (sans transport costs). These furnaces can sustain 1700°C max for 2 hours which is beyond the melting temperature of stainless steel. For larger furnace volume and amps you pay more. For hydrogen gas environment with safety features more again. Note this is the same machine that Zetamix sell under their own brand name for 3x the price. (Zetamix make ceramic and meta filaments.) You get support in that price however.
>under $3k on the bay. You cant touch a decent sintering oven for that.
You cant touch a decent sintering oven for that.
Thanks for playing! No Prize. Better luck next time.
not sure where the rest of my post went. There were more words when I hit enter?
If you convert €3k your already OVER $3k
You add in customs and shipping and you are well over $3k
You have proven my point.
sintered parts warp and distort. They require significantly more design planning and adjustment than SLM. The cost of 30-100W fiber lasers has dropped significantly over the last 5-10 years. Its quite approachable really. IF you are willing to deal with the potential hazards of metal powders.
Try:
https://www.alibaba.com/product-detail/1800C-High-Temperature-Laboratory-Oven-in_1600058399463.html
I agree with you regarding its draw-backs. Waiting 2 days and spending heaven knows how much on electricity to find that your job failed is unacceptable for most people.