Simulation Study on Microstructure Evolution and Mechanical Property Prediction of Ti60 Alloy

To predict the microstructure and mechanical properties of the Ti60 alloy by the simulation method is an important way for the material development. In this study, Ti60 alloy is converted into a Ti-Al-Mo ternary alloy based on its composition. On the foundation of establishing a quantitative thermodynamic data framework for Ti-Al-Mo alloys, a multiphase field kinetics model is developed to describe the bimodal microstructure evolution of Ti60 alloy, and by utilizing crystal plasticity finite element models, the mechanical properties of the microstructure obtained through phase field simulations are evaluated. The research reveals that with the increasing of heat treatment temperature, the volume fraction of the primary and secondary α phase decreases, and the the role of internal stress in variant selection is enhanced. Concurrently, the enrichment of Al within the α phase increases, while the depletion of Mo decreases gradually. During the bimodal deformation process, the β phase acts as the phase with high stress distribution, causing stress concentration around smaller secondary α phases. The average strain in primary α phases is notably higher than that in the secondary α phases. As the temperature rises, the lamellar thickens within the microstructure and the variant selection effects intensify, reducing the alloy’s stress coordination and uniform distribution, exacerbating uneven strain distribution and differential allocation characteristics, thereby decreasing alloy ductility. This study provides a model and data foundation for regulating the microstructural morphology of Ti60 alloy through heat treatment regimes.