SHORT-TIME BETA GRAIN GROWTH KINETICS FOR A CONVENTIONAL TITANIUM ALLOY

摘要

The kinetics of beta grain growth during short-time, supertransus heat treatment of Ti- 6Al-4V were determined using a salt-pot technique. The finite-time, subtransus temperature transient during salt-pot heating was quantified through measurements of the heat transfer coefficient characterizing conduction across the salt titanium interface and a simple heat conduction analysis which incorporated this heat transfer coefficient. Grain size versus time data adjusted to account for the subtransus temperature transient were successfully fit to the parabolic grain growth law d~n- d~n_o= kt exp(- Q/RT) using an exponent n equal to 2.0. Comparison of the present results to rapid, continuous heat treatment data in the literature for a similar titanium alloy revealed a number of semi-quantitative similarities.