Boron modified titanium alloys

Titanium and its alloys are extensively used in a variety of high performance applications with the α + β alloy, Ti-6Al-4V, being the most popular. Conventionally Ti alloys in the as-cast condition possess highly coarse prior β grains, whose size is in the order of ~mm. Such large grain sizes not only reduce the strength of the alloy, but also impair its workability. The addition of about 0.1% wt.% B can result marked reduction in the grain size. The advantages offered by microstructural refinements, thus induced by trace addition of B in Ti alloys, are reviewed in this paper. Processing response of the as-cast alloys improved as a result of grain refinement due to B addition, leading to the possibility of removal or minimization of primary ingot breakdown steps. This can significantly bring down the cost of the finished Ti alloy components. Microstructural refinements with B addition on the mechanical performance of the alloys both at room and elevated temperatures are reviewed with emphasis on the microstructure-property correlations.