Powder metals
Powder metals
(OP)
Just curious, what kind of strengths and notch sensitivity powder metal steels have? There seem to be alot of automotive parts made of this nowadays. Is it a desirable material or just a cost effective manufacturing technique?





RE: Powder metals
RE: Powder metals
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RE: Powder metals
We also use some powder metal cutting tools with no problems. There is also a lot blades for cutting polymer and fabric made from various alloys.
RE: Powder metals
Regards,
Cory
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RE: Powder metals
IE: price....
Just enough to do the job, and at the lowest cost is what we are required to do...
P/M parts are utilized effectively IMHO, when they can be.
Nick
I love materials science!
RE: Powder metals
In gear work we oil quenched after sintering, which gave us the toughness we needed to get thru durability testing. The oil helped lube the gears, too.
RE: Powder metals
Unless I'm missing something, P/M are a far cry from cheap. When you're comparing costs of steel, for example, be sure to include the expense of heat treat. That way, your comparison for resistance to wear, anyway, is more 'apples-to-apples'.
However, even when you factor in heat treat with steel, P/M metals, especially high speed steels, are comparatively more.
Advantages of P/M can come from their grain structure. By increasing alloy content, wear can be measurably improved without compromising toughness.
Hope that helped. Anyway, if you'd like information about surface treatments, like hardening, just see:
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Good luck!
William Gunnar
http://www.IndustrialCoatingsWorld.com
RE: Powder metals
PM for gears in only for light load applications, and again, the advantage is lower machining costs.
William Gunnar is correct that PM materials are expensive - very expensive. The final part cost may be lower due to lower manufacturing costs (like machining). He mentioned wear - PM is used for valve seats made from high alloy materials that have low formability, so the sintering route provides a way to make the part that isn't possible with conventional forming techniques.
Regards,
Cory
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RE: Powder metals
I have even converted low volume parts to PM because of machining costs. You have to modify the designs to allow for lower flexure, impact and fatigue strengths, but that is what we do.
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Plymouth Tube
RE: Powder metals
RE: Powder metals
Another process we introduced in gears was fine blanking, which is a precise blanking process. They were very durable. The blanked gears had the characterisitic flow shape on the side opposite the plunge tool. The reduced section of gear teeth was not objectionable. Strength is needed at the base of the tooth.
One war story: We were getting reduced gear strength, and when we started digging, we found that 2d shift mfg was induction HT and setting the gears aside for quenching as a group!
RE: Powder metals
PM has been replaced in many applications by MIM [metal injection molding] .
Like any good engineering a look at the whole picture will decide which material should be used.