Abstract

    At the last two Superalloy meetings at Seven Springs, work on the development of thermodynamic modelling tools for application to multi-component Ni-based superalloys has been presented. Such modelling has become quite widespread, providing significant benefit. However, its applicability often falls short from directly providing the information that is actually required and, by itself, cannot be directly used to model properties being targeted by the end user, e.g. TTT/CCT diagrams, mechanical properties, thermo-physical and physical properties. To overcome these limitations a new computer programme has been developed, called JMatPro, an acronym for Java-based Materials Properties software. The properties which can be calculated are wide ranging, including thermo-physical and physical properties (from room temperature to the liquid state), TTT/CCT diagrams, stress/strain diagrams, proof and tensile stress, hardness, coarsening of γ′ and γ″ and creep.

Introduction

    Thermodynamic modelling tools [1] are becoming increasingly used for Ni-based superalloys [2,3,4,5,6,7,8,9]. In themselves, such tools provide significant benefit. However, their applicability often falls short from directly providing the information that is actually required. For example, thermo-dynamic modelling helps towards the understanding of changes in phase constitution of a material as a function of composition or temperature. However, there is then a gap in translating this information into the properties being targeted by the end user, e.g. TTT/CCT diagrams , mechanical properties, thermo-physical and physical properties.

    To overcome these limitations a new computer programme has been developed [10,11] called JMatPro, an acronym for Java-based Materials Properties software. The properties which can be calculated are wide ranging, including thermo-physical and physical properties (from room tem-perature to the liquid state), TTT/CCT diagrams, stress/strain diagrams, proof and tensile stress, hardness, coarsening of γ′ and γ″ and creep.

A feature of the new programme is that the calculations are based, as far as possible, on sound physical principles rather than purely statistical methods. Thus many of the shortcomings of methods such as regression analysis can be overcome. It allows sensitivity to microstructure to be included for many of the properties and also means that the true inter-relationship between properties can be developed, for example in the mo-delling of creep and precipitation hardening. The purpose of the present paper is to describe the technical background behind the new program-me, giving extensive examples of its application and validation for multi-component commercial alloys.

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