APPLICATIONS OF PALM STEARIN AS A BINDER FOR INJECTION MOULDING OF BIOCOMPATIBLE MATERIALS

Abstract

A binder system is successfully developed for metal injection moulding of biocompatible materials, CoCrMo alloy powder The binder comprises a major fraction of palm stearin, which can be removed rapidly by solvent extraction and a minor fraction of polyethylene or polypropylene, which retains rigidity of the components. PE or PP can be removed by pyrolysis during ramping up to sintering temperature. Studies have been made to the feedstock compositions and to the process parameters in order to achieve high density components. Feedstock having a powder loading of the CoCrMo powder mixture up to 65 vol. % can be injection moulded successfully. Specimens can retain shape their shape during and after debinding. The final density achieved is higher than 97% of theoretical density and show a good mechanical properties.