Review: Microstructure Engineering of Titanium Alloys via Small Boron Additions (Preprint)
Abstract
Several studies, dating back to 1950s, were conducted on the addition of boron to titanium alloys, with an aim to improve the stiffness and strength. The majority of these efforts did not lead to successful transition due to shortfalls in mechanical property combinations and insufficient understanding of the effect of boron addition on processing-microstructure-property relationships. Recently, a team of researchers from the US Air Force Research Laboratory critically evaluated boron-modified titanium alloys to assess their applicability for aerospace applications. Several unique opportunities offered by boron-modified Ti alloys were discovered during these evaluations. Boron is essentially insoluble in titanium and precipitates as fine TiB whiskers. Small additions (~0.1 wt.%) of boron to titanium alloys were found to result in dramatically finer grain sizes in the as-cast condition. The presence of TiB precipitates restricts the grain growth at elevated temperatures, even above the beta transus. Together, these features offer the potential to develop affordable thermo-mechanical processing paths for titanium alloys.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2011
- Accession Number
- ADA549701
Entities
People
- D. B. Miracle
- S. Tamirisakandala