Development of Modified Arrhenius Model for Ti-6al-4v Alloy to Predict the Flow Stress

Strain, strain rate and temperature have a significant impact on the flow stress of a material. To study the impact of these factors on flow stress, experiments are conducted at various strain rates (0.1 0.0001s-1) and at various temperatures (323K, 348 K and 373K) on Ti-6Al-4V alloy. Stress values are taken for the corresponding strain values at an interval of 0.01(0.010.08). It is observed that the flow stress is a function of strain, strain rate and temperature. The sine-hyperbolic law in an Arrhenius-type equation has been successfully applied for prediction of flow behavior of materials. The original model has been revised several times to suitably represent the flow behavior of various grades of materials. In this model, an exponential strain-dependent parameter was introduced in the sine-hyperbolic constitutive equation to predict the flow stress. The combined effect of the temperature and strain rate on the deformation behavior is represented by the Zener–Hollomon parameter (Z) in an exponent-type equation. It is observed that the predicted flow stresses are in good agreement with the experimental data.