Powder metallurgy has already earned a reputation as a way to make metal components cost effective, thanks to the way its near-net-shape-manufacturing capabilities can cut down on machining costs and material waste. Now, a growing number of applications can take advantage of powder-metal technology. The industry's suppliers have made big strides when it comes to improving the mechanical properties of the parts they produce—particularly when it concerns strength, wear, and fatigue life. For a look at just how good powder metal can be, check out the winners from the 2005 International P/M Design Competition, held last month by the Metal Powder Industries Federation. The winners showcased not just traditional automotive jobs but also applications in laboratory equipment, medical devices, electrical devices, sporting goods, and power equipment. Here's a look at three winning parts in as many different materials.
For more information on the design competition and a look at the other winners, go to the MPIF website at:
BorgWarner Powdered Metals Inc. and BorgWarner Transmission Systems took home the competition's grand prize in the ferrous category for these input- and third-position outer races used in General Motor's 4T65-E transmission. Part of a new BorgWarner pawl-clutch design that replaces a sprag clutch, these parts are formed on a innovative tooling system that can handle the parts' elaborate features—which include pocket forms in the interior diameter and a wave form on the outer diameter of the input-position race. These races are robust, thanks to careful heat treating and surface densification procedures. After treatment, they exhibit an ultimate tensile strength of 131,000 psi and an apparent hardness of 32 HRC. The icing on the cake? The company estimates that the cost savings over forging these parts comes to 20 percent. For more information, visit http://rbi.ims.ca/4394-572.
This complex electrical connector took home the competition's award for a metal injection molded part. Made by Advanced Materials Technologies in Singapore, this copper powder part has a density of 8.8 g/cm3, a yield strength of 8,700 psi, an ultimate tensile strength of 36,000 psi, and an elongation of 45 percent. These properties allow the connector to hold up in its intended use—as a plug-and-play adaptor that allows appliance plugs to engage a power track. MIM helped save a bundle of money on this job—about 20 percent—by eliminating stamping, turning, machining, and press fitting. For more information, visit http://rbi.ims.ca/4394-573.
Made from 316 stainless steel by Webster-Hoff Corp., this support cover for a high-security military application highlights powder metal's precision manufacturing and net shape capabilities. As part of a statistical process control regimen, the company measures compaction levels and part weight every hour, holding a Cpk of 1.33 on level and holding weight to within 3 percent with a Cpk of less than 1.0. The company also holds key dimensional tolerances—flatness and slot width—to within 0.005 inches. As for net shape manufacturing, the cover needs only a deburring process. It has a density of 6.5 gm/cm3, an ultimate tensile strength of 41,000 psi, a yield strength of 34,000 psi, and a hardness of 59 HRB. For more information, visit http://rbi.ims.ca/4394-574.