Influence of powder type on processing and properties of components manufactured by MIM - Keith Murray, Sandvik Osprey Ltd., UK

The ever increasing adoption of Metal Injection Moulding (MIM) as the preferred manufacturing route for highly engineered, complex parts is due to a number of factors, including: competitive process economics, increasing capacity in the MIM supply chain, enhanced process capability enabling the manufacture of an expanding range of components and increasing awareness of the technology and its benefits amongst product designers. Selection of the optimum powder type is a key decision in extracting the maximum value from the MIM process.

In this paper, we review and compare the characteristics of gas and water atomised powders and describe the effect of gas atomised powder particle size distribution on processing and properties. It is proposed that the spheroidal shape and lower oxygen levels of gas atomised powders offer advantages not only in the stability of the MIM manufacturing process but also in the properties and consistency of the final components. Examples are drawn from different alloy families.