The North American powder metals (PM) industry is turning the corner this year with strong shipments, applications and sales.
“Basically, this market is exploding,” says Eric Boreczky, manager of automotive applications for Hoeganaes Corp., the world's largest PM producer.
The ability to produce precisely shaped metal components that reduce or eliminate the need for secondary operations such as machining continue to win new applications for PM.
Used primarily for powertrain and transmission components, PM's applications are projected to be at an all-time high in '04, creeping steadily into the unprecedented 40 lbs. (18.1 kg) per-vehicle territory in North America. However, the typical European car contains only 18.3 lbs (8.3 kg) of PM, the typical Japanese car 16 lbs (7.3 kg).
Most new engines contain powder-forged connecting rods and PM bearing caps, and PM continues to replace a variety of cast and stamped metal parts. But planetary carrier housings used in automatic transmissions and transfer cases are pushing PM towards higher per-vehicle poundage in '04. PM carriers withstand very high torque loads and offer cost savings to auto makers, proponents say. “These carriers represent one of the biggest future markets for ferrous powders our industry has ever seen,” adds Boreczky.
Kent Byrd, product technology manager at GKN Sinter Metals, a major automotive PM part producer, says planetary carrier housings are used in a growing variety of automotive applications and offer weight reduction as well as cost-saving benefits.
The complex, sinter-bonded transmission components are produced at net shape, eliminating much of the labor and additional machining processes needed to produce conventional cast-iron carrier housings. A total of 17 carrier housings have been converted to PM in the last four years alone, and more are on the way.
The carrier housing boom also is being fueled by an increase in PM supply capacity as well as changes in plant operations to accommodate PM usage.
PM engine variable valve timing (VVT) components also are growing in popularity among OEMs. The VVT systems optimize engine valve timing to enhance torque and fuel economy. Japan-based auto makers began heavily adopting VVT in the 1990s, but domestic OEMs — led by early-adopter Ford Motor Co. — are well under way with a shift to VVT for many of their engine families. VVT systems can potentially use 2 lbs. to 6 lbs. (0.9 kg to 2.7 kg) of PM parts.
The PM industry has seen a drop in some applications that do not require as much strength. Plastics are rapidly replacing small PM gears and interior parts. As a result, the PM industry is gravitating toward higher-strength, more highly engineered components and increasing the average density — a key factor in PM parts strength — of automotive parts.
Suppliers now require more high-density PM for engine and transmission components, and less low-density PM parts as they replace less demanding PM applications with robust plastics. Despite these lost applications, however, PM usage continues to increase.
Hoeganaes' Boreczky says the PM market will continue to grow in its two largest vehicle areas: powertrain and transmission. Applications such as connecting rods, valve guides, engine bearings, oil-pump gears, and complex drive and driven sprockets all are projected to see stable and possibly increased usage in upcoming model years.
— with Bill Visnic