An ICME Framework for Design of Stainless Steel for Sintering

Abstract

AbstractRecent progress in the development of integrated computational materials engineering (ICME) models offers new capabilities to deal with the challenge of designing multi-component alloys. In this study, a new type of computational method for efficient design of sintered stainless steel alloys, optimized for manufacturability (sintering) as well for performance, is presented. Development of the design method follows the materials systems approach that integrates processing, structure, and property relations during metal injection molding (MIM). It includes a multi-objective genetic algorithm (GA) to optimize alloy composition with the aim of improving the sintering as well as performance-related properties. To achieve this, the GA is coupled with computational thermodynamics and predictive analytical models. Thermodynamic simulations, based on the calculation of phase diagram CALPHAD method, are used to establish constraints through phase stability at equilibrium and calculate the diffusivity that determines the sintering behavior of the alloy. In addition, an advanced predictive model is used to determine solution strengthening. To demonstrate the capability of our method, a design exercise for austenitic stainless steel is presented. New alloys which are optimized for improved sinterability, yield strength, corrosion resistance, and cost are compared to 316L, a commercially available austenitic steel that is widely produced by MIM.