Shear Flow of Highly Concentrated Carbide Powder Suspensions

Rheological behaviour plays a key role in powder processing by powder injection moulding and extrusion. The flow behaviour of concentrated suspensions consisting of polymeric binder and metal powder is to a large extent determined by the characteristics of the binder system. This has to provide an acceptable flow during the forming process, proper interaction with the powder, and an easy extraction after moulding. Low molecular weight polymers and waxes are often the basis for polymeric binders, mainly because of easier mixing and removal of short polymer chains. Due to their complexity, considerable difficulty is encountered in interpreting the flow behaviour of highly filled polymer systems. The literature provides only a limited amount of data relating to such systems, especially when the polymeric vehicle consists of several components.