Injection moulding temperature and powder loading influence to the metal injection moulding (MIM) green compact

Abstract

The influence of temperature and powder loading on the Metal Injection Moulding (MIM) green compact is presented. The feedstock used is a mixture of stainless steel (SS316L) powder and a composite binder system consisting of polyethylene glycol (PEG) and polymethyl methacrylate (PMMA). The bimodal particle size distribution powder has a composition of 30 and 70% by weight of fine and coarse SS316L powder respectively with a powder loading of 64 and 65% by volume. The Battenfeld BA 250 CDC injection-moulding machine was used to produce a MIMA tensile specimen. The as-moulded density was measured using the Archimedes water immersion method according to the MPIF Standard 42. The injection temperature was varied from 120 to 150°C while the injection pressure remains at 350 bars. The three-point bending test was performed using INSTRON 5567 to measure the green strength according to the MPIF Standard 15. Results showed that the bi-modal feedstock with the higher powder loading was more sensitive to temperature and that the injection temperature was less significant to the as-moulded strength and density.