N. Saunders, Z. Guo, J. -. P. Schillé, A. P. Miodownik, Sente Software Ltd., Guildford, United Kingdom
A key element in thermo-mechanical processing practice and simulation of metallic alloys is the high temperature mechanical behaviour, particularly with respect to flow stress as a function of temperature and strain rate. It is therefore of substantial interest to develop physically based models that can both account for known experimental data and be applied to new and very different regimes with great confidence. This paper describes the recent developments of JMatPro, a computer software for material property simulation, on calculating high temperature strength and flow stress curves of titanium alloys. The first part of the paper provides a background to the related models for high temperature strength and flow stress curve modelling. The high temperature strength is found to be not only a function of microstructural changes in the material, but the result of a competition between two deformation modes, i.e. the normal tensile deformation and the deformation via a creep mode. Extensive validation has been carried out during the model development and is shown in the second part of the paper. Good agreement between calculated and experimental results has been achieved for a wide range of titanium alloys, including alpha, near-alpha, alpha+beta, and beta types. A feature of the new program is that the models 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.
Keywords: Titanium alloys; JMatPro; High temperature strength; Property simulation.
Summary: A key element in thermo-mechanical processing practice and simulation of metallic alloys is the high temperature mechanical behaviour, particularly with respect to flow stress as a function of temperature and strain rate. It is therefore of substantial interest to develop physically based models that can both account for known experimental data and be applied to new and very different regimes with great confidence.
This paper describes the recent developments of JMatPro, a computer software for material property simulation, on calculating high temperature strength and flow stress curves of titanium alloys. The first part of the paper provides a background to the related models for high temperature strength and flow stress curve modelling. The high temperature strength is found to be not only a function of microstructural changes in the material, but the result of a competition between two deformation modes, i.e. the normal tensile deformation and the deformation via a creep mode. Extensive validation has been carried out during the model development and is shown in the second part of the paper. Good agreement between calculated and experimental results has been achieved for a wide range of titanium alloys, including alpha, near-alpha, alpha+beta, and beta types. A feature of the new programme is that the models 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.
Keywords: Titanium alloys; JMatPro; High temperature strength; Property simulation.
