Powder Metallurgy (PM) is a continually and rapidly evolving technology embracing most metallic and alloy materials, and a wide variety of shapes. PM is a highly developed method of manufacturing reliable ferrous and non ferrous parts. The European market alone has an annual turnover of over six billion euros , with annual worldwide metal powder production exceeding one million tonnes.
PM parts are created by mixing elemental or alloy powders and compacting the mixture in a die with the resultant shapes then heated or “sintered” in a controlled atmosphere furnace to bond the particles metallurgically. The high precision forming capability of PM generates components with near net shape, intricate features and good dimensional precision pieces are often finished without the need of machining.
By producing parts with a homogeneous structure the PM process enables manufacturers to make products that are more consistent and predictable in their behaviour across a wide range of applications. In addition the PM Process has a high degree of flexibility allowing the tailoring of the physical characteristics of a product to suit the specific property and performance requirements.
Selecting the right materials means that the technical and mechanical properties of the finished product can be controlled.
PM is especially suited to the production of large series of pieces with narrow tolerances. Good performance in stress and absorbing of vibrations, as well as special properties such as hardness and wear resistance are a feature of PM components.
The Benefits of Powder Metallurgy
- Structural pieces with complex shapes
- Controlled Porosity
- Controlled performance
- Good performance in stress and absorbing
- Special properties such as hardness and wear
- Great precision and good surface finish
- Large series of pieces with narrow tolerances
So, like 3D Printing ?
Additive manufacturing is also known as 3D printing, rapid prototyping or freeform fabrication, and is “the process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies” such as machining. The term 3D printing can be defined as the fabrication of objects through the deposition of a material using a print head, nozzle, or another printer technology.” The use of Additive Manufacturing (AM) with metal powders is a new and growing industry sector.
Are there any downsides?
No process is perfect and PM has a few disadvantages to consider: the negative aspects of Powder Metallurgy include: the production cost of powder for metallurgy is very high, products can have limited shapes or features, worker health and safety needs to be ensured, high tooling costs means low volumes can be expensive, size and complexity of shapes is limited, parts can have low ductility and strength and certain metals in powder form can be fire or explosion hazards. Finally, the PM technique is not useful for low melting powder such as zinc, cadmium and tin as they show thermal difficulties during sintering operations.