Outstanding PM Parts Awarded
The 2008 Powder Metallurgy Design Excellence Awards Competition took place at the PM2008 World Congress in June. Several of the winning parts recognized were gears.
Mitsubishi Materials PMG Corporation, Tokyo, took home a grand prize in the automotive chassis category for a gear set with high strength used in a new tilting and telescoping steering column. The tooth lock and two cams making up the gear set were produced from diffusion-alloyed PM steels. They have a density of more than 7.05 g/cm³, a tensile strength more than 159,000 psi and a 57 HRA hardness.
In the hardware/appliances category, Capstan Atlantic of Wrentham, MA won the grand prize for a PM steel gear set (pictured) used in a high-volume business machine printer. Roll densified to a surface density of 7.8 g/cm³, the gear has an AGMA quality 10 precision level, and the pinion has an AGMA 8 level. The gear and pinion have a core density of 7.3 g/cm³, and the gear-tooth-surface fatigue resistance matches that of a wrought steel 8620 carburized gear. The single-pressed gear replaced two machined gears and saved more than 40 percent in cost.
A grand prize was awarded to Parmatech Corporation, Petaluma, CA, in the medical, dental category for a 17-4 PH stainless steel articulation gear that was used in a surgical stapling unit. This part was formed by injection molding to a density greater than 7.65 g/cm³ with tensile strength of 130,000 psi, a yield strength of 106,000 psi and a 25 HRC hardness. Finishing processes were unnecessary in the gear’s production, which saved 70 percent in cost.
A low-alloy steel intake and exhaust sprockets, used in a variable valve timing system for a high-performance, double-overhead cam V-6 engine, received an award of distinction in the automotive engine category. Produced by Cloyes Gear & Products Inc., Paris, AR, the sprockets used warm compaction to form to a density of 7.25 g/cm³. The high-strength timing sprocket achieves cam phasing functions. The sprockets have a typical tensile strength of 170,000 psi, a 52,000 psi fatigue limit and compressive yield strength of 183,000 psi.