Selection of elemental composition of a Nickel-based super alloy through neural networks and multi-criteria decision making

Abstract

ABSTRACT The present work aims to develop nickel-based superalloys by studying the impact of their alloying elements in providing the desired physical and mechanical characteristics. At present, materials are being developed using experiment-driven trial and improvement. The long time duration in their development rules out the planning of new materials and thus leading engineers to select the commercially available materials with a compromise towards the properties. The computationally developed materials have the potential to meet the needs of the materials engineers, and now the materials are being brought into the centre of the planning method. The selection of suitable elemental composition seems to be a multi-criterion decision-making problem with conflicting and diverse objectives as different elements execute different properties at varied conditions. Nickel is an adaptable element that can alloy with most metals. The present study deals with the procedure that can be applied to identify suitable elemental composition for a Ni based super alloy, allowing them to adjust for required properties in order to enhance its use in a particular application. The methodology deals with the selection of ‘n’ number of alternatives to give desired properties and applying multi-criteria decision-making algorithms to rank and select one among the alternatives developed. The Spearman rank correlation coefficient in the range of 0.74-1.00 shown a strong correlation between the methods adopted. From the analysis Cr (wt. 12%), Co (wt. 16.5%), Mo (wt. 2.5%), W (wt. 1.5%), Nb (wt. 1.5%), Al (wt. 2%), Ti (wt. 3%), Fe (wt. 1.5%), C (wt. 0.2%), and B (wt.0.03%) can be developed to get an yield strength of 504.94 MPa, Ultimate tensile strength of 678.62 MPa, % elongation 18.53 and Creep resistance at 1000 hours work life of 263 MPa to get better ductile properties. Also Cr (wt. 18%), Co (wt. 17%), Mo (wt. 4%), W (wt. 2%), Al (wt. 2%), Ti (wt. 1.5%), Fe (wt. 2%), C (wt. 0.1%) and B (wt.0.02%) can be developed to get an yield strength of 451.25 MPa, Ultimate tensile strength of 669.57 MPa, % elongation 25.18 and Creep resistance at 1000 hours work life of 309 MPa to get better strength properties.