Structure–property correlation of a boron and carbon modified as cast β titanium alloy

Abstract

Beta titanium alloys, Ti-15V-3Cr-3Al-3Sn, with minor additions of boron and carbon were prepared by consumable vacuum arc melting. Detailed microstructural characterizations were carried out using optical, scanning electron microscopes and transmission electron microscopes. Addition of boron resulted in refinement of the as cast beta grain while carbon addition resulted in the precipitation of extremely fine α phase during ageing. Formation of boride and carbide particles due to addition of boron and carbon, respectively, and refinement of the aged microstructure increased the hardness and strength as compared to the base alloy but reduced elongation to failure considerably, especially in the carbon-containing alloy where no measurable plasticity was observed. Fracture toughness values, however, were comparable for the boron- and carbon-containing alloys but these were lower than that of the base alloy.

Keywords:

• titanium alloys
• electron microscopy
• mechanical properties

Acknowledgements

The authors are thankful to DRDO for funding this research activity. The authors also like to thank the Director, DMRL, Hyderabad for his encouragement and permission to publish these results.