Constitutive Modeling of a Fine‐Grained Ti2AlNb‐Based Alloy Fabricated by Mechanical Alloying and Subsequent Spark Plasma Sintering

Abstract

The flow stress evolution of a fine‐grained Ti2AlNb‐based alloy fabricated by mechanical alloying and subsequent spark plasma sintering is experimentally acquired for different deformation conditions. Isothermal uniaxial compression test is conducted in the deformation temperature range of 950–1070 °C and the strain rate range of 0.001–1 s−1. Based on the experimental flow stress with friction correction, the modified Johnson–Cook model and strain‐compensated Arrhenius‐type model are established in the α2 + β/B2 + O triple‐phase and α2 + B2 two‐phase fields. The average absolute relative error (AARE) and determination coefficient (R 2) are 9.78% and 0.9858 for the modified Johnson–Cook model, and 4.19% and 0.9927 for the strain‐compensated Arrhenius‐type model. Compared with the modified Johnson–Cook model, the strain‐compensated Arrhenius‐type model is more suitable for predicting the high‐temperature flow stress of a fine‐grained Ti2AlNb‐based alloy fabricated by mechanical alloying and subsequent spark plasma sintering.