Direct ink writing of 17–4PH stainless steel using green binder: Rheological sensitivity and performance assessment

Abstract

Direct ink writing has emerged as a promising and cost-effective 3D stainless steel printing technique due to its capability in room temperature printing without a heat source. In this study, a novel solvent-based cellulose-derivative binder was incorporated to form a yield-pseudoplastic colloidal ink suspension up to 54.9 vol% (or 91.5 wt%) solid loading, improving shrinkage predictability. Rheological sensitivity analysis is used to construct a printability boundary for stainless steel printing with the cellulose-derivative binder. The method proposed in this paper offers attractiveness over conventional powder bed fusion, particularly in avoiding the challenges associated with loosely packed powder handling and environment safety. Moreover, it addresses environmental concerns by making use of non-toxic and eco-friendly binder. A comprehensive analysis of rheological study was conducted to identify parameters affecting printability and shape retention by varying the binder concentration and metal content. Through the sensitivity rheology analysis, the outcome yields exceptional printing quality and demonstrates its capability in producing complex parts. The sintered performance: achieving 93.6 % density at a sintering temperature of 1360 °C, minimal carbon content (0.033 wt%), with a hardness of 35.8 HRC and xyz-shrinkage of 10.81 %, 10.78 %, and 11.85 %, respectively which has high performance competitive value to technologies currently dominating the market like atomic diffusion additive manufacturing and bound metal deposition.