Powder metal services are used to create finely divided or powdered metals that are used in fabricating sintered parts, thermal spraying, filling plastics, and other specialized applications. Powdered metals include most types of metals.
Powder metallurgy is the process of making metal parts and components by heating compacted powdered metals to just below melting. Powder metallurgy is also known as press-and-sinter. Many metals are treated with this process to produce porous materials called sponge fines. For example, iron sponge fines are small particles of iron ore that have been reduced by heat. Sponge iron can come in lumps or finer particles and is frequently used as an alternative to steel scrap metal.
The advantages to using this method to create metal parts include elimination of much of the waste of traditional machining, the ability to create a wide variety of alloyed components, and the ability to heat-treat materials for increased strength.
Types of Powder Metal Processes
Metal powders are made using a variety of techniques. Powdered metal can be milled, atomized, precipitated, or blended to proper consistency and texture for a specific use.
- Milling processes make metal powders through a milling machine which physically grinds the metals to a powder form. Milling is not generally used for metals that are combustible in powder form.
- Atomizing processes make metal powders by separating molten metal into small droplets that are then frozen solid.
- Precipitating processes make metal powders which are high in purity and can be made in precise particle sizes. Some metal powder is made through electrolysis resulting in high-purity, high-density powder made of copper and magnesium.
- Blend processes make mechanically alloyed metal powders. These are mixtures of powders that are crystallized at atomic levels, forming a compound with uniformly dispersed particles, ensuring the final product’s high strength.
Many other metal powders are pre-alloyed, meaning that every particle in the powder mixture contains more than one element. Metal powders are used to make all kinds of metal parts, and are also used in sintering applications, polyester fiber spinning, injection molding, and brazing.
Selecting a powder metal service can be based on a number of different factors, including design specifications, process capabilities, or material types. The GlobalSpec SpecSearch Database allows the user to specify the desired service based on services such as high volume production and design. assistance, process types such as mechanical pressing or sintering, materials such as aluminum and steel, and density ratios such ranging from fully dense to open porosity.
Applications of Metal Powders
Powder metal services are used to create products for a number of applications including magnetic composites, printing, surface coatings, friction materials, food supplements and additions, polymer filtration, chemical processes, and welding.