The influence of trace boron addition on grain growth kinetics of the beta phase in the beta titanium alloy Ti-15Mo-2.6Nb-3Al 0.2Si

Trace boron additions to the P titanium alloy Ti-15Mo-2.6Nb-3Al-0.2Si (wt.%) lead to significant grain refinement of the ascast microstructure and precipitation of TiB whiskers along the grain boundaries. The TiB is very effective in restricting the P grain boundary mobility by Zener pinning. A model is developed to predict the maximum grain size as a function of TiB size, orientation and volume fraction. Good agreement between model predictions and experimental results was obtained. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.