In the June 21 issue of Machine Design we presented the Grand Prize winners of the annual Powder Metallurgy Design Excellence Awards handed out by the Metal Powder Industries Federation.
Here are more innovative PM parts that captured the MPIF judges' eyes, winning Awards of Distinction:
The Automotive — Transmission award of distinction went to a two-part assembly (sprocket-assembly drive and sprocket driven). The three-level sprocket from Capstan Atlantic, Wrentham, Mass., serves in an SUV transfer case. And it features a precision-machined tooth radius, hub diameter, and tapered inside diameter. The sprocket is made from a modified MPIF FL-4405 PM material to a density of 7.4 gm/cm3 with an apparent hardness of 45 HRC. And its tensile strength exceeds 200 kpsi. The sprockets are carbo-nitrided for tooth-wear resistance.
LAWN & GARDEN/ OFF-HIGHWAY
Judges handed out two Lawn & Garden/Off-Highway awards of distinction.
The first went to Burgess-Norton Manufacturing Co., Geneva, Ill., for left and right-hand actuator arms used in zeroturning-radius controls of commercial and residential riding lawnmowers. The PM arms are made from MPIF FC 0208-50 material and replace two six-piece assemblies. This eliminates 12 parts and related labor and assembly costs. The actuator arms incorporate a bevel gear and stop lug into a lever that controls a hydraulic system. They feature a density of 6.7 gm/cm3, a tensile strength of 50 kpsi, and a hardness from 75 to 100 HRB.
NetShape Technologies Inc., Cambellsburg, Ind., captured the second award of distinction in this category for a differential carrier gear made for Ariens Co., Brillion, Wis. The net-shape par t goes in a transmission for the Ariens professional Snothro line of 8.5-hp-and-higher snow blowers. The design improved drive torque output by speeding up the pinion and increasing the ratio after the friction disc in the transmission. The gear enables remote locking and unlocking of the differential. The complex five-level par t has density of 6.8 g/cm3, a minimum tensile strength of 75 kpsi, a transverse rupture strength of 130 kpsi, a yield strength of 90 kpsi, and a fatigue limit of 34 kpsi. Parts need secondary quenching and tempering.
SSI Technologies Inc., Janesville, Wis., won the Hardware/Appliances award of distinction for PM and MIM parts used in tactical hinge-style handcuffs made by ASP Inc., Appleton, Wis., a lawenforcement products supplier. The handcuffs use 14 PM parts processed by conventional or high-temperature sintering. Five are different designs — a lock pawl, bow, side and center links, and main links. The bow has a tensile strength of 103 kpsi, and has a large 0.090-in. radius in the areas where it touches the wearer's wrist. These radii had been machined in the previous design. Twelve parts are made from three stainless-steel materials and two parts are made from MPIF FD0405-60 steel. The four main links are made by MIM to a minimum density of 7.5 gm/cm3 and have a tensile strength of 78 kpsi. Three modified 316 stainless-steel parts and two duplex stainless steel MIM parts make up the linkage assembly. The patent-pending design lets the assembly be swaged together without rivets.
The Hand Tools/Recreation award of distinction went to PMG Holding S.A., Mamer, Luxemborg, for a stainless-steel camshaft pulley made for Yamaha Marine Co. Ltd., in Japan. The pulley operates in the timing control mechanism for a four-stroke 115-hp outboard motor. It has an outer diameter of 4.36 in., which is considered large for PM stainless steel. It is made to a density of 6.7 gm/cm3 and has tensile and yield strengths 49.3 and 21.75 kpsi, respectively. Production of the large pulley required a special powder-mixing technique of first coating the particles with a liquid binder, then adding a substantial amount of a special lubricant. Precisely controlled vacuum dewaxing completely removes the additives. Machining the inner diameter counter bore is the only secondary operation.
Kinetics, a Climax Engineered Materials Co., Wilsonville, Oreg., earned the Medical/Dental award of distinction for a 316L stainless-steel MIM pin shroud made for ArthroCare Corp., San Juan Capistrano, Calif. The part goes in the Opus Magnum Knotless Implant device for arthroscopic surgical repair of torn rotator cuffs. The implant device secures a sutured tendon to the shoulder bone. The pin shroud is implanted into a patient. The near-net-shape pin has a typical density of 7.85 gm/cm3 and tensile and yield strengths of 78 and 29 kpsi, respectively. MIM replaced an assembly made by laser-welding three wire-EDM parts. The single MIM part reduced final assembly time from 15 to just 5 min/unit.
INDUSTRIAL MOTORS/CONTROLS & HYDRAULICS
Webster-Hoff Corp., Glendale Heights, Ill., and its customer, Norgren Automotive Inc., Mt. Clemens, Mich., took the Industrial Motors/Controls & Hydraulics award of distinction for a PM aluminum lever block. The part goes in a quick-change vacuum cup system that handles parts and materials, or both. It has a density of 2.45 gm/cm3 and tensile and yield strengths of 16 and 7 kpsi, repectively.
Next year's winners will be announced during the 2008 International Conference on Powder Metallurgy & Particulate Materials held at the Gaylord National Hotel in Washington, D.C., June 8–12, 2008.
Metal Powder Industries Federation,
(609) 452-7700, www.mpif.org