Optimization of Injection Parameters Using 16µm Stainless Steel Powder (SS316L) at 63 Vol. %, 63.5 Vol. % and 64 Vol. % Powder Loading by Taguchi Method for Metal Injection Molding

Abstract

In this paper, injection molding parameters are optimized using the L18 Taguchi orthogonal array for mechanical strength and surface quality of the green part. The feedstock used consists of stainless steel powder (SS316L) with the powder loading of 63 vol. %, 63.5 vol. % & 64 vol. %. The binder compositions used are polyethelene glycol (PEG-73 wt.%), polymethyl methacrilate (PMMA-25 wt.%) and stearic acid (4 wt.%). Mould temperature, injection temperature, injection pressure, injection time, holding time and powder loading ware selected as signal factors using Taghuci’s method based on literature, where these parameters were significant in MIM. Results showed that the optimum parameters are: mold temperature at 650C, injection temperature at1450C, injection pressure at 650 bar, injection flow rate at 20 m3/s, holding time at 5 s and powder loading of 64 vol.%. Analysis of Variance (ANOVA) result shown that mold temperature is the most influence in order to produce good green part’s surface quality while powder loading give the best result for green part’s strength.