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 β titanium alloy Ti–15Mo–2.6Nb–3Al–0.2Si (wt.%) lead to significant grain refinement of the as-cast microstructure and precipitation of TiB whiskers along the grain boundaries. The TiB is very effective in restricting the β 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.