Boron modified titanium alloys

Titanium and its alloys are extensively used in a variety of high performance applications with the alpha + beta alloy, Ti-6Al-4V, being the most popular. Conventionally Ti alloys in the as-cast condition possess highly coarse prior beta grains, whose size is in the order of similar to 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.