DEVELOPMENT OF INJECTION MOULDED CO-CR-MO ALLOY POWDER USING PALM BASED BINDER

Abstract

Metal Injection moulding (MIM) is an advanced near net shape forming process for high quality of complex shapes combined with high properties of materials. For economic reasons, it is necessary to have demand for a large quantity of parts. This paper presents the attempt to manufacture metallic implant using CoCrMo alloy powder by MIM process. The CoCrMo alloy powder with the median particle size of 15 μm and a binder consisting of palm stearin and poly ethylene were mixed at 160°C using a sigma-blade mixer for one hour to prepare the feedstock of the test bar. The test bar was injection moulded using vertical injection moulding machine with the nozzle temperature of 200°C. Prior to sintering, the specimens were debound using a combination of solvent extraction and thermal pyrolysis method. The specimens were then sintered under vacuum at the temperature between 1350ºC to 1390ºC. The properties of the sintered bar such as physical appearance and densities were presented and discussed.