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A new face-centred-cubic phase is reported here in a metastable β-titanium alloy with an equilibrium α–β structure, formed due to solution treatment and ageing. The face-centred-cubic phase is located inside the close-packed-hexagonal α-phase and has an orientation relationship with α-phase. This new phase could be observed only in thin foils used for transmission electron microscopy. The stability of the new phase is discussed and its presence in thin foils is explained. [ABSTRACT FROM AUTHOR]

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 fineαphase 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. [ABSTRACT FROM AUTHOR]