Mechanical behavior of Ti-6Al-4V at high and moderate temperatures - Part I: Experimental results

This study investigates the plastic deformation of titanium alloy Ti-6%Al-4%V under low and moderate strain rates and various temperature conditions. Mechanical testing is performed in the temperature range 650-1340 K (710-1950 degreesF) and under constant strain rate loading ranging from 10(-3) to 10 s(-1). The test results are correlated with the evolution of the microstructure and compared to published data. The flow stress of this alloy is strongly dependent on both temperature and deformation rate, with the temperature effect becoming negligible in the upper part of the temperature range investigated. At temperatures above 800 K (980 degreesF) the flow stress decreases sharply with temperature. The effect of deformation rate on this transition is investigated and the possible mechanisms responsible for the behavior are discussed. Based on these experimental results, a physically-based constitutive law is developed in the sequel of this paper. (C) 2002 Elsevier Science B.V. All rights reserved.