Flow behavior of commercial grade Ti-6Al-4V with lamellar structure in isotherm forging and kinetic analysis of process

• Main Authors: H. Omidvar, B. Fallah Ghanbary, M. Tamizifar
• Format: Article
• Language: fas
• Published: Isfahan University of Technology 2011-12-01
• Series: Journal of Advanced Materials in Engineering
• Subjects: ti-6al-4; kinetic analysis; isothermal forging; globularization.
• Online Access: http://jame.iut.ac.ir/article-1-526-en.html

In this paper, plastic flow behavior and micro structural evolution of Ti-6Al-4V alloy in temperature range of 750-1050 °C and strain rate range of 0.001-0.1 (S-1) in isotherm compression condition were investigated. The purpose was to estimate activation energy of globularization of lamellar structure and analyze this process kinetically. True Stress-strain curves obtained at the temperatures below 950 °C indicate a limited amount of flow softening imputed to a dynamic recrystallization occuring at about 950 ˚C. In contrast, at higher temperatures, the flow stress increases linearly with plastic strain until at temperatures about 1015°C where flow stress becomes nearly independent of the temperature. By analyzing flow stress data via Zener-Hol-lomon and sellars equation, Q activation energy of dynamic recrystallization was estimated and structural equation of plastic flow was obtained, whixh were comparable to results raeched by other investigators.