Flow behaviour of powders during die filling

In this paper, the powder behaviour during die filling is discussed. Initially, methods used to test powder flow properties are reviewed and a novel method based on the measurement of critical shoe velocity is emphasised. It is shown that this method not only can be used to characterise the flow of powders, but it can also be used to assist process design in powder metallurgy and similar operations. The powder behaviour during die filling is then discussed in two successive stages: the flow of powder from a shoe and the packing of powder inside a die. Previous studies are reviewed and typical behaviour of powder during die filling is summarised. Finally, segregation during die filling is also discussed and further studies on die filling are suggested.