Hot deformation behavior, microstructure evolution and processing map of Cu–2Be alloy

Abstract

The hot deformation characteristics of Cu–2Be alloy is studied within the temperature range of 650–950 °C and in strain rate of 0.001–1 s−1. The constitutive analysis and adaptive-network-based fuzzy inference system (ANFIS) were constructed for describing the hot deformation behavior. It is perceived that the developed ANFIS model can be used to accurately predict the hot deformation characteristic of the studied alloy. Corresponding equations for peak stress/strain are achieved and then, processing maps are developed based on the dynamic material model (DMM) theories. The results display that at lower strain, the deformation dissipation (η) increases with increasing temperature and decreasing strain rate; however at higher strain levels, η exhibits a noticeable decline at 900–950 °C and 0.01 s −1, in which momentous grain coarsening tends to happen. At high strain level, the optimal hot deformation domain of studied alloy should be at 850–950 °C and strain rate of 1–10 s−1, in which more uniform and fine grain structure is dominant due to the discontinuous dynamic recrystallization (DDRX). The correlation of recrystallized grains size with Z is determined in terms of power law. Moreover, the unstable flow regions are described in the processing maps using Prasad instability criterion.

Keywords

• Cu–2Be alloy
• Hot deformation
• Constitutive equation
• ANFIS
• Processing map
• Flow instability