The Metal Powder Industries Federation (www.mpif.org) issued awards for outstanding PM parts developed for the major industry sectors in 2006 which again highlighted PM’s significant cost savings, design benefits, and special properties.
The sectors included:
- lawn & garden/off-highway
- hand tools/recreation
Automotive PM part award winners
Grand prize – automotive engine category
A PM aluminium camshaft bearing cap (Fig. 1) made by Metal Powder Products Co.’s Washington Street Div., St Marys, PA. for General Motors Powertrain Pontiac, Mich. won the grand prize in the automotive engine category. Designed originally for PM, two caps are used in GM’s new High feature V6 engine, operating in various GM brands, including the Cadillac CIS, SRX and CTX, Buick LaCrosse and Rendezvous, and Saab 9-3.
It is the first dual overhead cam engine using a single cam cap across both camshafts. Press and sintered to net shape, the multi-level part has an ultimate tensile strength (UTS) of 117MPa, and a hardness range of 85-90 HRH. Choosing PM over an alternative manufacturing process such as die casting, provided an estimated 50% cost saving by eliminating pre-assembly machining steps. The PM caps requires only one line boring step during installation.
Grand prize – automotive transmission category
Stackpole Ltd., Carrier Systems Div., Stratford, Ontario, Canada, won the automotive transmission grand prize for a planetary gear output carrier (Fig. 2) also made for GM Powertrain. The carrier contains three steel PM parts (two spiders and a one-way clutch plate) weighing a total of 4kg. The PM parts are sinter-brazed into the Le Pelletier planetary gear output carrier, which contains two separate decks of pinion gears.
It is the first three-piece Le Pelletier carrier assembly made by the PM process. The parts are produced to minimum density of 6.8 g/cm3 have an UTS of 448 MPa and 85 HRB hardness. The carrier operates in GM’s new Hydra-Matic 6L80 six-speed rear-wheel drive automatic transmission, with a warranty of 200,000 miles, or more, of service. It debuts in the 2006 Corvette, Cadillac STS-V and XLR-V, and several models of GM’s new 2007 full-size SUVs equipped with the Vortec 6.2L V-8engine.
Award of distinction – engine category
Metaldyne Corp., Plymouth, Mien., won the award of distinction in the engine category for a new fracture split camshaft cap (Fig. 3) made for MWM International, Sao Paulo, Brazil. The steel cap is used in several diesel engines, including 2.8L, 3.0L and 4.2L engines operating in different models of light trucks and trucks. The 3.0L engine contains five caps adding 1.75kg of PM per engine.
The cap is made to a density of 6.8 g/cm3. Its mechanical properties include: yield strength (YS) of 433 MPa; UTS – 560 MPa; fatigue strength of 175 MPa; and minimum 80 HRB hardness. As the first low density PM part using fracture splitting technology, the PM design eliminates almost 60% of machining time and cost, and the expense of locator bushings required with cast iron caps.
Award of distinction- automotive transmission category
PMG Ohio Corporation, Dayton, Ohio, won the award of distinction in the automotive transmission category for a steel one way clutch (OWC) race (Fig. 4) made for General Motors Powertrain. The high-strength part is used in the GM 4T40/45E automatic transmission, operating in Chevrolet, Pontiac and Saturn vehicles.
The PM race undergoes a proprietary surface densification process on the part’s complex, non-cylindrical geometry. The process ensures full density on the cam surface, a contact fatigue strength of more than 3,615 MPa, and a tensile fatigue strength of 765 MPa. These values match forged heat-treated steel.
The race’s minimum bulk density is 7.4 g/cm3. Surface densification offers a cost effective alternative to conventional forging, powder forging or broaching a steel tube. Secondary operations performed on the part include drilling six oil holes and turning counterbores.The race passed severe validation testing, achieving a B10 life of 521,000 cycles and a torque value of 312 Mm.
Non-automotive PM part award winners
Grand prize – lawn & garden/off-highway category
PM steel parts, a drum and two pulleys (Fig. 5), operating in a premium power lawn mower blade override system (BOS) won the grand prize in the lawn & garden/off-highway market category. Burgess-Norton Mfg. Co., Geneva, III., produces the parts with a density of 6.9 g/cm3. They have an UTS of 280 MPa, and a 50-80 HRB hardness range.
PM allowed a moulded key on the pulleys and hexagonal pockets on the drum that receive the lawn mower blade bolts. The large and small pulleys are sinter bonded into a single component. PM provided more than 20% cost savings over previous assemblies of machined, cast and stamped parts. Annual production is is said to exceed 300,000 PM parts.
Grand prize – hardware/appliance category
Hawk Precision Components, Sinterloy Facility, Spring Grove, III. won the grand prize in the hardware/appliance category for a copper-infiltrated steel latch bolt actuator (Fig. 6) which provides an estimated 35% cost saving.
The zinc-plated PM part actuates three latches as a security feature in a swinging patio door. It is connected to and controlled by the door handle. Formed to a density of 7.3 g/cm3, the complex part has nine geometric levels. Properties include: 410 MPa yield strength, 600 MPa UTS, 3% elongation, 1,140 MPa transverse rupture strength, 230 MPa fatigue limit, and 89 HRB hardness.
Grand prize – hand tools/recreation category
A high speed PM M2 steel tool bit (Fig. 7) made by Pacific Sintered Metals, Los Angeles, Calif. won the grand prize in the hand tools/recreation category. The bit functions in a hand tool used to install tubes in heat exchangers by expanding and locking the tube in place.
The part is pressed and liquid-phase sintered to full density at 8.1 g/cm3 followed by heat treatment to 61-63 HRC hardness and triple-tempered for toughness. Its thin sections and multiple steps are moulded to a near-net shape. The customer – Cooper Tool – grinds the edge for sharpness. PM not only outperformed machined wrought M2 bar stock but also provided a 90% cost savings.
Grand prize – electronic/electrical components category
Intricate metal injection moulded (MIM) parts, a flip slider and hinge barrel (Fig. 8), won the grand prize in the electronic/electrical components category. The parts are made by Advanced Materials Technologies Pte Ltd, Singapore using 17-4 PH stainless steel sintered to a density of 7.6 g/cm3.
Properties include: UTS of 1,185 MPa, YS of 1,090 MPa, 6% elongation, and 30 HRC hardness. The MIM parts make up the dual-hinge opening mechanism in Motorola’s PEBL mobile phone.
The innovative design positions the clamshell phone cover to slide down and flip open in a single movement. The MIM process allowed a very complex thin wall, overhanging structures and three-dimensional design. Both parts are coined, machined, polished and plated. Machining these parts, an alternative fabrication method, would have cost five times more than MIM.
Award of distinction – lawn & garden/off-highway category
Fansteel American Sintered Technologies, Emporium, PA, won the award of distinction in the lawn & garden/off-highway category for a lawn mower blade brake clutch input hub (Fig. 9).
Made to a density of 6.7 g/cm3 its properties include: UTS of 410 MPa, YS of 380 MPa, fatigue strength of 340 MPa, and 60 HRB minimum hardness. PM provided 55% cost savings for the user Warner Electric, South Beloit, Ill.
Award of distinction – hardware/appliances category
Made by Capstan Atlantic, Wrentham, Mass., a PM sinter hardened steel crankshaft gear used (Fig. 10) in a residential standby generator engine won an award of distinction in the hardware/appliances category.
The high-precision 18-tooth 27 degree helical gear with a 25mm face width is produced first as an AGMA class 7 gear. Subsequent processing steps include boring, facing, broaching a keyway, and gear rolling to AGMA class10 accuracy. The part has a density of 7.0 g/cm3, a yield strength (YS) greater than 450 MPa, 520 MPa tensile strength UTS), and an apparent hardness range of 52-60 HRA.
Award of distinction – hardware/appliances category
Precision Powdered Metal Parts, Inc., Pomona, Calif, won the other award of distinction in the hardware/appliances category for a door latch retractor assembly (Fig. 11) made for Kaba llco Corp., Winston-Salem, N.C.
Used in airport jet way door Grade 1 combination locks, the assembly has four parts made from copper-infiltrated steel; an outside sleeve cam, outside sleeve, inside sleeve and retractor. The parts have a 550 MPa UTS, 480 MPa YS, and a 160 MPa fatigue limit. PM replaced imported investment castings that had tolerance control problems and surface finish defects.
For further information on any of the MPIF Award winners contact James Dale ([email protected]).