Looking for and engineer with MIM experience

[EdStainless]

So I am working with somebody who is having some stainless steel (17-4PH) parts made by metal injection molding.
The supplier has now decided that there are some things that he can’t (doesn’t want to) do.
After tooling has been built and parts sampled.
I need some help in figuring out which issues are real and which are just complaining.
Ed

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P.E. Metallurgy

 

[hendersdc]

Ed,

I am only passively familiar with the process so I won't be the best source of help for you but I would be interested in seeing what your supplier is having trouble hitting, any chance you can provide more details and some pictures or is confidentiality involved?

 

[EdStainless]

At this point confidential, but that may change.
These are firearms parts.
You have three things to worry about with MIM, tolerance of the specific feature, overall tolerance, and general surface condition and uniformity. It looks like he is having issues with all three to various degrees.
The parts that I have seen have all kinds of issues, and look nothing like the pre-production ones. My hunch is when and inexperienced operator runs them at normal production settings they come out like crap and when an experienced operator runs a small lot they come out fine.
I am trying to figure out what questions to be asking.

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P.E. Metallurgy

 

[hendersdc]

So the preproduction samples looked good, no changes were made to the tool, and then the next round of parts are junk? Sure sounds like process issues/changes to me. Have you seen any of the green parts? Would the issues you have seen with the finished parts be visible at that stage? That could help you track down which stage of the process they are having issues with.

 

[arunmrao]

Ed,

In my limited experience of understanding Direct Metal Printing for firearm parts, the performance of these fail. Traditionally manufactured parts like starting from forge stock, machining heat treating, finishing has proved better.

MIM acceptance as a technology has a long way to go before being accepted for such critical parts.

"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.

 

[bobjustbob]

Arunmrao,
MIM parts are all over the firearms industry for internals such as hammers, sears, disconnects, etc. and have been for years. When I was in college 20 years ago we toured a MIM facility who were making safety levers for 1911's. We are not talking about barrels or slides. However, one company did print an entire 1911 with a metal printer. The first was a 17-4PH and I think they did a second out of Inconell, I could have those two reversed.

Bob

 

[dgallup]

MIM has been around for decades and is very well suited for many automotive and firearms application to name just a few. I released my first high volume part over 25 years ago and it wasn't new then. Additive manufacturing is just as old but it keeps evolving. The capabilities are all over the place depending on the process. GE is making single crystal turbine blades with additive manufacturing in volume and cheaper than castings.

Ed - sounds like one of the cheap off shore MIM houses that promise the moon but don't have good enough process and quality control. If they quoted and made good prototypes and now are backpedaling then I think you need to look at better sources. I know piece price is important but if you have to do extra inspection, rework or reject lots and it shuts down production the cheap part ends up increasing total cost.

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[DVWE]

Arunmrao,

bobjustbob hit the nail on the head. Many firearm 'traditionalists' scoffed at the process when it first came out over 20 years ago (just like they did when the first 'plastic' Glocks came out). Now there are few that don't use the process.

The devil is in the details; she also wears prada.