MultOpt++: a fast regression-based model for the development of compositions with high robustness against scatter of element concentrations
A. Müller, I. Roslyakova, M. Sprenger, P. Git, R. Rettig, M. Markl, C. Körner, R. Singer.
Modelling and Simulation in Materials Science and Engineering, IOP Publishing, 27, 024001, (2019)
Alloys-by-design is a term used to describe new alloy development techniques based on numerical simulation. These approaches are extensively used for nickel-base superalloys to increase the chance of success in alloy development. During alloy production of numerically optimized compositions, unavoidable scattering of the element concentrations occurs. In the present paper, we investigate the effect of this scatter on the alloy properties. In particular, we describe routes to identify alloy compositions by numerical simulations that are more robust than other compositions. In our previously developed alloy development program package MultOpt, we introduced a sensitivity parameter that represents the influence of alloying variations on the final alloy properties in the post-optimization process, because the established sensitivity calculations require high computational effort. In this work, we derive a regressionbased model for calculating the sensitivity that only requires one-time calculation of the regression coefficients. The model can be applied to any function with nearly linear behavior within the uncertainty range. The model is then successfully applied to the computational alloys-by-design work flow to facilitate alloy selection using the sensitivity of a composition owing to the inaccuracies in the manufacturing process as an additional minimization goal.
Keyword(s): sensitivity; CALPHAD; regression analysis; alloys-by-design; superalloys