Thursday, December 01, 2022

All you wanted to know about Metal Injection Molding,

or maybe you didn't but it's interesting.  I knew a little about it, this series at RevolverGuy covers it with quite a bit of detail.

I will throw in that when he talks about all the chips produced by machining, that stuff does not get thrown away, it's all saved and sold back to a foundry.  They know exactly what steel/aluminum alloy/bronze/whatever the stuff is, which makes the foundry very happy to get it.  Not having to deal as much with the chips can be a handy thing.


pigpen51 said...

I don't have the time now to go and look, but I spent over 35 years at a shop that made steel for the investment cast industry, and we got a lot of scrap back from the places that we sold metal to. Among the places was Sturm Ruger, and Pine Tree Castings, in Arizona and in New Hampshire. I have seen parts of guns, frames and even internals, come back in their scrap.
These alloys included everything from 416 w/Sulfur to 17-4. And of course, the tool steels. 416 always had either Sulfur or Selenium added, in order to make machining easier. I was told it made the chips break up better, or some such thing.
We also made alloys under high vacuum for the aerospace industry, such as jet engines or ground based turbines.

Anonymous said...

Quite an interesting article about MIM. Something I knew little about except for a few mentions in gun magazines.

Country Boy said...

There are several articles about Tesla's use of MIM to produce chassis sections for their cars. One mentions that it reduces the parts count in part of the chassis from around 70 parts, to just one. Here are links to the articles. No details, but still interesting.

markm said...

Country Boy: That's interesting, but it's not MIM, where the mold is filled with a metal powder plus a binder. It's conventional casting (squirting molten metal into a mold) on a very large scale, such as a one-piece cast aluminum car chassis. If it works _and the production quantities are high enough_ this should substantially reduce the cost of the chassis or other big parts. But I think the mold-making, setup, and casting machine will be very costly, so you only save if you can sell millions of cars.

...And most states in the USA and other countries don't have the spare electrical generation capacity to charge very many electric cars, and are actually shrinking their available-on-demand capacity. Would you buy an e-car if you knew you'd have to wait for the wind or sun to be right before you could recharge it?