Modeling the high-temperature constitutive relationship of Ti-22Al-25Nb alloy based on fuzzy theory

The hot deformation characteristics of Ti-22Al-25Nb alloy were studied in the temperature range of 940-1030°C and strain rate range of 0.001-10 s^-1 using Gleeble 1500 thermal simulator. Based on the results obtained from the experiment for the complex flow deformation behavior, a constitutive model of Ti-22Al-25Nb alloy was established with the help of the fuzzy set theory. Simultaneously, a kind of fuzzy dynamic linear model was put forward to extract the feature of sample data for the complicated nonlinear relationship of thermodynamic parameters. Compared with the experimental value, the results of this study indicate that the method is feasible to construct a constitutive relationship model for this alloy and high in the degree of fitting. It can be used to make up for the limitations that traditional regression can not reflect the whole deformation process. It is not only a wide prospect of application but also a convenient way to characterize the constitutive model for Ti-22Al-25Nb alloy.