Powder metallurgy (PM), also known as powder forming, is the technology of combining various metallic powders to produce solid parts with target shape and geometries, through a range of operations that include compaction, sintering, and heat treatment.
Powder metallurgy processes can be used to produce any possible part shape, as long as it is suited to the powder mixture of materials being used. Applications include automotive, aerospace and medical parts.
There are several stages in a powder metallurgy process.
1. The first is powder preparation, which entails the selection of raw materials, such as metal powders, and their sieving and blending to reach the desired composition.
2. The next stage is compacting, which involves the use of a die-press of the desired shape and size to compress the raw powder into the shape and size required.
3. Once compacted, the parts are vacuum-sintered, during which the compacts are heated to near their melting point, with the added pressure from the vacuum allowing them to form the desired shape without the need for additional machining.
4. The last stage is heat treatment, in order to achieve the desired properties for the part, such as hardness and ductility. This stage is completed before the parts can be used for their intended purpose.
The advantages of powder metallurgy include greater strength and tolerance, better precision and accuracy, and parts with complex shapes can be formed easily. Additionally, it is a cost effective process as it eliminates the need for machining, and offers a quicker solution to production.
The biggest disadvantage of the process is that it relies heavily on the use of specialized equipment, such as die presses or vacuum furnaces, which can be costly and might not be available in some areas.
Overall, powder metallurgy is a cost effective and time efficient technique to create complex parts, regardless of its initial material form, and is thus applicable for many industries. Examples include automotive, aerospace and medical parts. It is also a good alternative to traditional machining processes, as it offers more accurate and consistent parts with greater strength and improved tolerances. It is therefore a valuable option for manufacturers to consider for their projects.
