Winners of the 2011 Powder Metallurgy Design Excellence Awards Competition, sponsored by the Metal Powder Industries Federation (MPIF), were announced at PowderMet2011, International Conference on Powder Metallurgy & Particulate Materials, 18-21 May in San Francisco, USA.
Grand Prize Awards
Parmatech Corporation, Petaluma, Calif., USA, earned the grand prize in the hand tools/recreation category for a large-game 420 stainless steel hunting arrowhead, the 300Xtreem broadhead, made for Optek Precision Tooling Ltd.
Fabricated by the metal injection moulding (MIM) process, the thin blade features a critical straightness necessary for accuracy and the external thread for attachment to the arrow shaft is moulded in the design.
The part is formed to a final density of 7.7 g/cm3 and has a 48–52 HRC hardness range. Going the metal injection moulding route saved 50% of the cost of machining the broadhead from stainless steel bar. The customer sharpens the arrow head edge, the only secondary operation performed.
FloMet LLC, Deland, FL., USA, earned the grand prize in the medical/dental category for a housing cup and lid used in an audio device with magnetic shielding capabilities. This application is the first of its kind in the high-power audio device sector.
The anti-magnetic MIM material with high nickel content provides electromagnetic interference, or EMI shielding, preventing interference from other electronic signal sources. While the cup has four thin walls for proper assembly, the new lid design must fit securely into the cup opening; this prevents moisture and/or foreign matter from entering the housing, as well as maintaining the EMI shielding capability.
Manufactured to 8.30 g/cm3 density, the parts have an ultimate tensile strength of 84,000 psi, yield strength of 32,000 psi, and a 40% elongation. Alternative manufacturing processes such as deep drawing, casting, and machining would have required multiple components. Combining these multiple components through the MIM process provided significant cost savings, in addition to eliminating up to 40% of scrap loss.
Awards of Distinction
A rear sight used on sporting and military rifles such as the AR-15, M4, and M16 models, received the award of distinction in the aerospace/military market category. Made by Megamet Solid Metals, Inc., Earth City, Mo., USA, for its customer, Yankee Hill Machine Co., Inc, the nickel steel MIM part features very close tolerances and a complex geometry requiring an elaborate tool design.
The sight allows the shooter to target objects at ranges up to 200 yards by using the larger aperture, and to target objects at longer ranges by flipping the sight down and using the smaller aperture. The part is made to a density of 7.5 g/cm3 and has an as- sintered ultimate tensile strength of 55,000 psi.
Choosing the MIM process over investment casting provides a 40% cost saving. Secondary operations are limited to tapping and nitride finishing.
Indo-US MIM Tec (P) Ltd., Bangalore, India, won an award of distinction in the hand tools/recreation market category for a 17-4PH stainless steel hammer used in a Leatherman Tool Group multi-purpose military utility tool (MUT) designed for military and law enforcement personnel, and civilians.
Made by the MIM process, the intricate complex part performs five of the MUT’s 27 functions. It is formed to a density of 7.5 g/cm3 and has an ultimate tensile strength of 175,000 psi, yield strength of 158,000 psi, heat-treated 35–40 HRC hardness, and a minimum 6% elongation.
Secondary operations include threading two tapped holes, age hardening and glass-bead blasting, and an optional blackening treatment performed by Leatherman.
A 17-PH stainless steel distal channel retainer formed via the MIM process by Kinetics Climax Inc., Wilsonville, Ore., USA, received the award of distinction in the medical/dental market category. The complex, multi-level part is the main distal-side component of an articulation joint in an articulating mechanical stapler/cutter used in endoscopic surgery. Formed to a typical density of 7.7 g/cm3, the part has a typical tensile strength of 175,000 psi, yield strength of 158,000 psi, and a 6% elongation.
The MIM process provided a cost saving in the range of 25 to 30% vs. other design options. Kinetics performs precision sizing and reaming.
More information: www.mpif.org