Powder metallurgy (PM) continues to make inroads into the automotive, aerospace, industrial, and consumer markets as evidenced by the winners of the 2010 Powder Metallurgy Design Excellence Awards Competition. The awards, sponsored by the Metal Powder Industries Federation (MPIF), were announced at PowderMet2010, the 2010 International Conference on Powder Metallurgy & Particulate Materials, in June.
MPIF officials noted that many of the winners stretched the limits of powder metallurgy techniques. Winning parts also received kudos for cutting costs, eliminating secondary operations, and greening production processes.
Metals on the move
In the Automotive transmission category, GKN Sinter Metals, Auburn Hills, Mich., took the Grand Prize for the industry-first fully integrated planetary carrier and rocker-style one-way clutch assembly it designed and made for Ford Motor Co., Dearborn, Mich. The cam plate, spider, clutch hub, and rocker plate combine with 12 steel rocker struts and springs, a retainer plate, and snap ring replace a two-piece riveted planetary carrier in Super Duty truck five-speed automatic transmissions.
The parts are PM copper-steel and sinter-hardened materials, assembled with a sinter-hardened cam plate single-pressed to a density of 7.25 g/cc without warm compaction and high-temperature sintering. Secondary operations are limited to machining the bearing journals, oil holes, and pinion holes. The PM assembly is 25% less expensive than the riveted one.
An Award of Distinction in the Automotive transmission category went to PMG Indiana Corp., Columbus, Ind., for a one-way clutch outer race made for EXEDY Globalparts Corp., Belleville, Mich. Used in a torque-converter stator, the heavily loaded part transmits more than 202 lb-ft of torque which produces high Hertzian contact stresses on the cam surface and high tensile stresses in the hoop area. A proprietary surface densification process forms the inner surface of the race to a minimum density of 7.7 g/cc while preserving durability.
The Automotive engine category saw an Award of Distinction for PMG Füssen GmbH, Füssen, Germany. The company’s complex PM steel crankshaft sprocket made for a V-6 engine by iwis motorsysteme GmbH & Co. KG in Germany, is a multi-level part with a density of 7.0 g/cc. The part also has yield strength of 45,000 psi and tensile strength of 54,000 psi. The part ID is pressed and machined after sintering to high-precision tolerances.
In the Hand Tools/Recreation category, Smith Metal Products, Lindstrom, Minn., won the Grand Prize with a 17-4 PH stainless steel hunting arrow tip. The metal-injection-molded (MIM) shuttle T-lock broadhead made for Trophy Taker, Inc., Plains, Mont. has an unusual shape that could not be produced in commercial quantities with any other technique.
The part has a final density of 7.6 g/cc, yield strength of 137,000 psi, and tensile strength of 159,000 psi. The ferrule hardness is 36 HRC and the blade hardness is 38 HRC. Secondary operations are limited to final grinding of a razor-sharp edge on the tip of the ferrule and the leading edge of the blade.
An Award of Distinction went to Burgess-Norton Mfg. Co., Geneva, Ill., for its final belt-drive PM steel sprocket which transmits torque from transmission to rear wheel on a motorcycle and replaces a sprocket made from hobbed cast iron. A 770-ton CNC hydraulic compacting press forms the outside-diameter flange on the top and a center web on the bottom, a combination of features not possible with conventional compacting technology.
The high-volume part has 50,000-psi tensile strength and 80-HRB apparent hardness with a 50-HRC-hardness, steam-oxide surface treatment. PM saved up to 30%, improved wear and corrosion resistance over the wrought part, eliminated machining scrap and coolants, and cut part weight for better fuel efficiency.
An upswept grip safety used in the 1911-style 45-caliber pistol made by Colt’s Manufacturing Co., LLC., West Hartford, Conn. won an Award of Distinction for Megamet Solid Metals, Inc., Earth City, Mo. MIM forms the complex 17-4 PH stainless-steel part to a density of 7.6 g/cc and eliminates extensive secondary machining required for the previously investment cast part. MIM also cut part cost, reduced customer lead times, increased production rates, and produced a more uniform part.
Advanced Materials Technologies Pte Ltd., Singapore, won the Grand Prize in the Industrial motors/Controls and Hydraulics category for four complex 316L stainless-steel MIM parts. The lock cover, lock-barrel pin, lock-barrel boss, and lock-barrel square assemble into a locking device for heavy machinery operating in harsh environments.
MIM let Advanced Materials skip surface polishing, enhance corrosion resistance, and cut part cost 30%. The 7.5-g/cc parts have tensile strength of 75,000 psi, yield strength of 25,000 psi, 50% elongation, and 67 HRB hardness. They resist over 300,000 cyclical rotations and a 48-hour salt-spray test.
Two Awards of Distinction in this category went to Lovejoy Sintered Solutions LLC, Downers Grove, Ill. One part, a PM steel rotating machine counterweight used in a refrigeration compressor for truck trailers, replaces a two-piece design that required machining the bolt and threaded holes in addition to separate tooling and presses for both parts. The 6.7 to 7.0-g/cc part has a tensile strength of 47,000 psi and 57–60-HRB hardness as well as twice the fatigue resistance of the two-piece version. Lovejoy was also able to eliminate a thread-locking fluid that emitted volatile organics.
Lovejoy’s second winning part, developed with its customer Rosta AG in Switzerland, is a PM steel tensioner assembly used in a belt or chain-drive system. The assembly previously required sawing, stamping, welding, and roll-printing of an angle scale on the part. The PM part eliminates waste, lets Lovejoy press the protractor in to the arm, and cuts part cost 26%. Made to a density range of 6.2 to 6.9 g/cc, the parts have 43,000-psi ultimate tensile strength, yield strength of 39,000 psi, and 70-HRB hardness.
Lock, shock, and printer
In the Hardware/Appliances category, ASCO Sintering Co., Commerce, Calif., won an Award of Distinction for a high-strength, sinter-hardened PM steel deadlocking lever made for Stanley Security Solutions, Inc., Indianapolis, Ind. The lever, for a 40H-series high-security mortise lock, is warm compacted and sintered to a density of 7.0 g/cc, then impregnated with resin, deburred, zinc plated, and chromated. It has a 145,000-psi ultimate tensile strength, a 9.5-ft-lb impact strength, a 40,000-psi fatigue strength, and a 30-HRC hardness. Eliminating a milling operation greened ASCO’s process and cut costs 40%.
Capstan Atlantic, Wrentham, Mass., also won an Award of Distinction in this category for a high-density transfixed pinion gear and sector used in a high-volume printing application. Formed to a density of 7.3 g/cc, the parts have a 195,000-psi tensile strength, 185,000-psi yield strength, and a 75,000-psi fatigue limit. The pinion gear is selectively roll-densified and crowned for bending-fatigue resistance and rolling-contact-fatigue resistance, and both parts are hardened for wear resistance. The parts have twice the service life as previous versions and meet AGMA Q9 precision level.
In the Aerospace/Military category, FloMet LLC, DeLand, Fla., won the Grand Prize for a safe and arm rotor used in Department of Defense explosive device. The MIM 316L stainless-steel part, formed to 7.6 g/cc, has numerous outside radii and angular surfaces including 12 functional features and surfaces that are geometrically controlled by concentricity, profile, and true position tolerances. Its significant properties include ultimate tensile strength of 75,000 psi, yield strength of 25,000 psi, 50% elongation, 140-ft-lb impact strength, and 67-HRB hardness.
Advanced Materials Technologies Pte, Ltd., www.admaterials.com.sg
ASCO Sintering Co., www.ascosintering.com
Burgess-Norton Mfg. Co., www.burgessnorton.com
Capstan Atlantic, www.capstanatlantic.com
Colt’s Manufacturing Co., LLC, www.coltsmfg.com
EXEDY Globalparts Corp., www.exedyusa.com
FloMet LLC, www.flomet.com
Ford Motor Co., www.ford.com
GKN Sinter Metals, www.gknsintermetals.com
iwis motorsysteme GmbH & Co. KG, english.iwis.com
Lovejoy Sintered Solutions, LLC, www.lovejoy-inc.com
Megamet Solid Metals, Inc., www.megamet.com
Metal Powder Industries Federation, www.mpif.org
PMG Füssen GmbH, www.pmgsinter.com
PMG Indiana Corp., us.pmgsinter.com
Rosta AG, www.rosta.ch
Smith Metal Products, www.mimparts.com
Stanley Security Solutions, Inc., www.stanleycss.com
Trophy Taker, Inc., www.trophytaker.com
U.S. Department of Defense, www.defense.gov