Numerous industries utilize solid metal parts made of powdered metal. Powdered metal components, which are made from powdered metal via powder metallurgy, can be found in applications spanning across industries such as lawn and garden, computer, electronics, hardware, and automotive.
More specifically, powder metal parts include magnetic assemblies, filtration systems, structural parts, and automobile components. Powder metal gears are inherently porous and they naturally reduce sound, making them a suitable component to the sintering process. Bearings and bushings can simply be produced by way of sintering, however, they may require a secondary sizing operation because their fabrication leaves little room for error.
Powder metal is soft and can be formed in a variety of shapes with proper sintering; however, this variety is very limited. Powder metal is a popular choice of material for parts with magnetic properties, and its magnetism can be enhanced through the sintering process. Two processes can be utilized to make powder metal parts: sintering and metal injection molding. Both of these processes are used to produce powder metal parts made of aluminum, copper, and iron.
Sintered metal parts include sintered steel and sintered bronze parts, and they are made by melting metal powder and forming it into a shape. The metal injection molding process involves adding wax, resin, or polymers to powdered metal, heating the mixture to a pliable state, and formed within a mold. Read More…
Powder metallurgy is a process in which metal is formed and fabricated from powder to a finished part. The raw metal material is made into powder by way of atomization, mechanical alloying, electrolytic techniques, chemical reduction, and pulverization. The powder is then mixed with a lubricant, which assists in reducing friction between the powder material and the pressing dies. The next step involves forming, in which the material is molded, forged, or pressed. Sintering is a crucial step in the process, as it develops the products finished properties, such as regulating its porosity and increasing its strength.
In the high-temperature process of sintering, the compacted raw materials, also known as green parts, are melted down in a furnace. When the green parts are melted, the particles are bonded together while still retaining the part’s shape. Sometimes, the product requires secondary operations such as machining, deburring, sizing, or heating. The finished parts may appear solid, but they are actually made up of tiny capillaries that are interconnected with each other. Thus, the parts have a porosity of 25%.
Sintered metal products have many advantages over parts that are fabricated through other processes. Sintering uses roughly 97% of materials, and therefore does not produce as much waste. Sintered products are not sensitive to the shapes in which they are formed, and they frequently do not need to undergo any secondary operations. Powder metal parts have controlled porosity, enabling them to self-lubricate and filter gases and liquids. Because of all of these benefits, powder metallurgy is a highly recommended process in fabricating parts that require intricate bends, depressions, and projections. A wide variety of composites, alloys, and other materials can be used in the sintering process to fabricate products of numerous designs and shapes.
Metal injection molding is a powder metallurgy process which is frequently used to produce metal parts that are smaller, more complex, high density, and high in performance. The process of metal injection combines powder metallurgy and plastic injection molding, and is commonly used for parts used in industries such as electronics, computer, hardware, firearms, dental, medical, and automotive. Metal injection molding allows for more freedom in detailing and design, reduces waste, and offers products that are magnetic, more corrosion-resistant, stronger, and denser. However, this process is only used in making thinner, smaller parts, and is more costly than regular powder metallurgy.
Metal injection molding differs in a few ways. First, the metal powder is not only mixed with lubricants, but also with thermoplastics. The parts are only formed by molding using standard plastic injection molding machines. The next step involves using chemicals or thermal energy and an open pore network to remove the thermoplastics from the parts. Finally, the parts are sintered and undergo secondary procedures if necessary.
Bronze, steel, iron, brass, copper, and aluminum are just a few of the many metals that can be converted to powder and undergo the metallurgy process. Aluminum is frequently used because it is highly flammable, highly conductive, and light in weight. Aluminum is a popular materials to use in structural applications and pyrotechnics. Copper is highly conductive both electrically and thermally, and are thus popular for use in electrical contractor or heat sink applications.
Iron contains a graphite additive and is frequently used to fabricate bearings, filters, and structural parts. Steel is used for tool steel or stainless steel powders, are very high in strength. Thus, one application for which it is frequently used is automobile weight reduction. Finally, bronze is a metal that is higher in density and has a higher mechanical performance than brass, and bronze metal parts are commonly utilized to fabricate self-lubricating bearings.