Metal Injection Moulding Parameters Optimization and Interaction Study Using Taguchi Method

Abstract

In this study, the Taguchi method is used to find the optimal moulding parameters for the metal injection moulding (MIM) feedstocks. Parameters optimised are injection temperature (factor A), mould temperature (factor B), injection pressure (factor C) and flow rate (factor D). Feedstocks used were water atomised stainless steel powder with a solid loading of 62 %Vol and the multicomponent binder consisting  PEG, PMMA and strearic acid. Green defects and green density were considered as quality characteristics (response) and optimised by using Taguchi’s L81 (3⁴⁰) orthogonal array. Green defects evaluated using parameter design for discrete data technique while green densities were measured according to the MPIF standard 42. The signal-to-noise (S/N) ratio and analysis of variance (ANOVA) are employed to investigate the quality characteristics. The analysis results show that the mould temperature (factor B) is the most significant factor affecting the quality characteristic. The optimal conditions for the green defects and green density are A₁B₂C₀D₁ and A₂B₂C₁D₀ respectively. The influences of the two-factor interactions and three-factor interactions cannot be neglected.