Five Cost-Cutting Powder-Metal Part Designs

July 23, 2014
Can’t decide between machining and 3D printing? Powder-metallurgy techniques might be your answer.
Download this article in .PDF format
This file type includes high-resolution graphics and schematics when applicable.

Powder-metallurgy (PM) processes, including metal injection molding (MIM) and conventional press-and-sinter technology, are indispensable for production in industries like automotive. That’s because PM processes generate complex parts in far less time than machining and in larger quantities.

Engineers can create complex designs for PM parts that cut weight from machined alternatives. Meanwhile, additive-manufacturing methods try to accomplish the same feats, but PM processes continue to prove higher strength and quality than 3D-printed counterparts.

To recognize companies pushing the envelope with PM manufacturing, the Metal Powder Industries Federation, Princeton, N.J., recently awarded 14 prizes at the 50th anniversary Powder Metallurgy (PM) Design Excellence Awards competition. The event was held at the 2014 World Congress on Powder Metallurgy & Particulate Materials earlier this summer. All five Grand Prize winners and nine Award of Distinction winners touted the cost-saving benefits of producing PM parts.

Grand prize in the automotive — engine category

These gasoline direct-injection (GDI) pumps could be the most-complex production assembly ever made by metal-injection molding.
in India won its prize for a MIM assembly that controls fuel flow in gasoline direct-injection (GDI) pumps made for Stanadyne Corp., Windsor, Conn. The four parts include a blank discharge check, a stop-discharge check valve, a valve-discharge check, and a CRV spring seat. Three of the parts are made of 440C stainless steel, and the fourth is made of 17-4 PH.

Indo-US MIM says this could be the most-complex, high-volume assembly ever made by MIM. It’s 35% less expensive than traditional versions, plus performs better. MIM lets engineers modify hole geometry to enhance flow dynamics for a 10 to 20% boost in fuel economy. The most complicated part, the blank discharge check, has intercrossing holes made by a machine using tooling with six side cores — three of which move independently.

Grand prize in the automotive transmission category

This is a 32-part planetary-carrier assembly for a HF35 hybrid transmission. The manufacturer compresses the parts and then sinters them together.
, St. Marys, Pa., won for a planetary-carrier assembly. Made for Ford Motor Co., the 32-part assembly completes the HF35 hybrid transmission that goes into Lincoln MKZ, Ford C-Max, and Ford Fusion hybrid vehicles. It’s the first gearing of this type to go in an automotive transmission.

Keystone estimates the assembly is 25% less expensive than traditional alternatives. It’s been in production for more than two years, with about a quarter of a million assemblies shipped, and none have been returned.

Before joined to the shaft, Keystone compresses the spider and carrier plate and sinter-brazes them together. They also sinter-forge the helical pinion gears to full density using tools that rotate to match the gears’ 24.5° angle.

Grand prize in the lawn-and-garden and off-highway category

This copper-steel disengagement mechanism goes in a snow blower, and won an award because of the complex processing the manufacturer developed to make them.
, Wrentham, Mass., won this award for copper-steel parts made for General Transmissions Inc., Brownsville, Tex. The parts make up a disengagement mechanism for a snow-blower differential, which lets the user pivot the blower in place by disengaging a wheel. As a new technology in this product category, this differential could set a new standard for tight-turning functions on similar machines.

Capstan makes the two parts in 11 pressing levels. Precisely timed ejectors and sophisticated robotics help get the parts out of punches without cracking them. Despite design complexity, the manufacturer forms these parts to net shape, and special sintering fixtures maintain flatness and level-to-level relationships.

Grand prize in the medical and dental category

These 5-mm tissue-fusion tines have geometry that’s far more precise than those made by traditional modes of manufacturing.
, an ARCMIM Co., DeLand, Fla., won for two 5-mm tines — one fixed, one moving — that go into a thermal tissue-fusion and dissection tool. Called the Altrus, the tool is made by ConMed LLC, Utica, N.Y., and uses direct thermal energy and pressure to seal, transect, dissect, and coagulate tissue.

Previous versions of the tool didn’t include any MIM parts, but now all of the parts are MIM. The parts are 17-4 PH stainless steel, yet they don’t have any of the molding and processing limitations of previous models. More specifically, MIM gives the manufacturer a fixed tine with a very precise length and rib width. MIM also makes tines that are straighter than the old tines. FloMet uses thermal processing to finish the tines, and ConMed gets them preassembled.

Grand prize in the electronic and electrical components category

These powder-metal parts act as a nozzle assembly for sound-isolating earphones.

FloMet won another award for a three-piece net-shaped audio assembly, made for microphone and audio-equipment manufacturer Shure Inc., Niles, Ill. The parts — made by MIM from 316L stainless steel — include a nozzle interface, outer nozzle, and metal collar that go into high-end sound-isolating earphones. (The earphones are unique in that they let the user customize frequency responses.)

FloMet must make the net-shape parts low cost (so the earphones aren’t overly expensive) but still cosmetically pleasing with a clear exterior. Here, MIM works better than traditional manufacturing because it’s unlikely to get enough precision out of die-cast or machined parts, and still keep costs down. Plus, such processes wouldn’t meet the application’s material-performance requirements.

To see the nine Award of Distinction winners, click here.

About the Author

Lindsey Frick | Associate Editor

Lindsey has been an Associate Editor for Machine Design since 2012. She holds a Bachelor of Science in mechanical engineering from Cleveland State University. Prior to joining Penton, she worked in product design, packaging, development and strategy, and manufacturing. She covers the materials market and other areas of interest for design engineers such as 3D printing and methods to operate efficiently.

Sponsored Recommendations

The entire spectrum of drive technology

June 5, 2024
Read exciting stories about all aspects of maxon drive technology in our magazine.


May 15, 2024
Production equipment is expensive and needs to be protected against input abnormalities such as voltage, current, frequency, and phase to stay online and in operation for the ...

Solenoid Valve Mechanics: Understanding Force Balance Equations

May 13, 2024
When evaluating a solenoid valve for a particular application, it is important to ensure that the valve can both remain in state and transition between its de-energized and fully...

Solenoid Valve Basics: What They Are, What They Do, and How They Work

May 13, 2024
A solenoid valve is an electromechanical device used to control the flow of a liquid or gas. It is comprised of two features: a solenoid and a valve. The solenoid is an electric...

Voice your opinion!

To join the conversation, and become an exclusive member of Machine Design, create an account today!