Construction for processing map based on DMM and identification for the stable hot-working parameters of Ti-6Al-2Zr-1Mo-1V alloy
Several series of billet samples were compressed on heat physical simulation machine under deformation temperatures 1073-1323K and strain rates 0.01-10s-1,then the true stress-strain data collected resulted the performance of calculations for strain rate sensitivity(m-value),power dissipation efficiency(η-value) and instability parameter(ξ(e·-value).A series of 3D surfaces reveal the dramatic response of m-value to the transferring and coexisting of several deformation mechanisms induced by the enhanced effect of stress,temperature,strain rate and strain,from which the stable and unstable deformation parameter regions were indentified preliminarily.In further,the maps of power dissipation efficiency were plotted,from which the unstable(η≤0) deformation parameter regions were indentified furtherly.Finally,based on the map of instability criterion,stable region(ξ0),unstable region(ξ≤0) were clarified clearly.According to the comprehensive identification,the stable deformation parameter regions with higher m-value level,higher η-value level,higher ξ-value level are recommended,while the unstable deformation parameter regions with negative m-value level,negative η-value level,negative ξ-value level should be avoided.