Content area
Full Text
This article describes the development of a new multi-platform software program called JMatPro for calculating the properties and behavior of multi-component alloys. These properties are wide ranging, including thermophysical and physical properties (from room temperature to the liquid state), time-temperature-transformation/ continuous-cooling transformation diagrams, stress/strain diagrams, proof and tensile stress, hardness, coarsening of [gamma]' and [gamma]'', and creep. A feature of the new program is that the calculations are based on sound physical principles rather than purely statistical methods. Thus, many of the shortcomings of methods such as regression analysis can be overcome. With this program, sensitivity to microstructure can be included for many of the properties and the true inter-relationship between properties can be developed, for example in the modeling of creep and precipitation hardening.
INTRODUCTION
Tools that utilize thermodynamic modeling to explore the equilibrium and phase relationships in complex materials are being used increasingly in industrial practice.1 These tools provide significant benefit, but they often fail to directly provide the information required. For example, thermodynamic modeling helps toward 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 targeted by the end user, (e.g., time-temperature-transformation [TTT] diagrams, mechanical properties, and thermo-physical and physical properties.
The jump from thermodynamic calculation to the final understanding of materials properties is significant. It can usually only be achieved through further experimentation if quantitative information is required or through the knowledge and experience of the user if guidance of a more qualitative nature suffices. To overcome these limitations, a new computer program has been developed2 called JMatPro, an acronym for Java-based materials properties. The program was developed to augment the thermodynamic calculation by incorporating various theoretical materials models and properties databases that allow a quantitative calculation for the requisite materials property to be made within a larger software structure.
THERMODYNAMIC CALCULATIONS
The current software utilizes core minimization routines developed for the PMLFKT software program by Lukas et al.3 and recently extended by Kattner et al.4 to multicomponent alloys. These subroutines have been converted from Fortran to C and, in addition, a comprehensive set of new subroutines written in C/C++. These new subroutines provide a variety of benefits, including...