Powder metallurgy

The properties of a component produced using powder metallurgy are highly dependent on its underlying microstructure. This, in turn, depends on the properties of the raw materials and process conditions used. In a fixed process, the biggest source of variation comes from the materials. Inconsistent material properties will result in inconsistent finished component properties. To produce components of consistent quality with powder metallurgy, it’s therefore crucial that manufacturers can understand and optimize their material characteristics.

Particle size and particle shape are critical parameters in powder metallurgy processes, because they affect important properties such as powder flow, powder packing, and interparticle friction. These properties must be optimized to achieve the required strength and density in the green body and sintered components. Chemical composition is also very important because the metal powder needs to comply with the alloy composition of the material specified, which can affect the properties of the finished part.

Crystallographic structure also affects the mechanical properties of both the metal powder and the final component. For this reason, powder production and powder metal parts manufacturing processes need to be engineered to produce materials with the right phase composition, grain size, and texture for the required application – all while minimizing residual stresses .

Finally, for processes such as metal injection molding, where the feedstock material is a dispersion of powder in a polymer/wax matrix, the rheological properties of the feedstock become critical. These properties are influenced by particle characteristics including particle size, shape, and concentration, as well as binder properties such as molecular weight and molecular structure. Manufacturers must therefore be able to control these characteristics.

To support AM manufacturers with material characterization in powder metallurgy processes, we offer several analytical tools. For particle characterization, our main solutions are the Mastersizer 3000 and Morphologi 4 – benchtop instruments with a high level of automation. The Mastersizer 3000 uses laser diffraction to measure particle size distribution. This technique can also be employed online using our Insitec instrument. For particle shape analysis, the Morphologi 4 automated imaging system uses a digital camera to capture high-quality 2D images of dispersed particles, and provides particle-specific size and shape information.

For elemental analysis, we offer X-ray fluorescence (XRF) solutions, which are available in floor-standing (Zetium) and benchtop (Epsilon) variants, depending on application requirements. And, to support structural and crystallographic analysis, X-ray diffraction (XRD) is our principal solution, which we also offer in both floor-standing (Empyrean) and compact (Aeris) systems. Finally, for determining the molecular weight and structure of polymeric materials, the Omnisec is our main solution, using gel permeation chromatography.