As we’ve said time and again, the sintered bearings sector represents an important part of the powdered metal fabrication industry. After all, this is an engineering principle that produces self-lubricating bearings. Imbued with that beneficial feature, a bearing functions without a separate oil feed mechanism. None the less, this technology doesn’t limit itself to this one application. Just where else is powder metallurgy processing making a name for itself?
Innovative Powder Metal Applications
Compacted from exotic metals and exposed heat, porous metal components are popping up everywhere. They’re found in magnetic assemblies, the electromagnetic cores that control strong eddy currents when an alternating current utilizes a high-frequency waveform. In vehicles, clutch hubs and engine sprockets call upon the self-lubricating feature we’ve so carefully regaled in past articles. On stepping away from an oily substance, state-of-the-art filtration systems are currently embracing metal elements in their assemblies. Amazingly, that porous metal, although it looks solid, functions as a top-of-the-line filter.
What is Powdered Metal Fabrication?
Low noise gears use powder metal components because of their sound reducing build. MRI scanners take the same approach, with rare earth materials providing sintered magnetic power. How are these important parts fabricated? Let’s introduce Metal Injection Molding (MIM). It’s a fabrication technique that produces geometrically complex parts, so the powdered metal manufacturing sector needs this capability. Similar to the plastics molding process, the fine metal powder is fed into a cavity. A special thermoplastic additive binds the metal, then that additive is dissolved by a solvent before the newly profiled component enters a furnace.
Controlling Secondary Operations
Designed to produce net-shape constructs, not many other fabrication techniques enter the operation. The metal can be cut, but those abrasive events must be properly controlled, for the cutting action influences the porous crevices on the surface of that abraded interface. Typically, this fabrication work seals the sponge-like surface, although further finishing work may be required to assure that finish. Otherwise, these net-shape constructs are fully processed during the compressive operation. Isostatic pressing, for example, uses powder metallurgical science to create dense metal components, including the turbine blades used in aircraft engines. Essentially, this latter pressing method uses gas and heat to force a flexible mold into a desired shape. Inside that mold, the powdered metal bows to the uniformly applied pressure and forms into a single metal component.
Conventional fabrication methods are sometimes used to cut and shape simple geometrical profiles. However, when we’re fabricating a detailed metal part, one that’s made from powdered metal, it’s one of the above compression systems that takes charge. Isostatic pressing or metal injection molding, the production run gains its intended outlines without sacrificing that all-important porosity feature.