METHOD OF BIPHASIC TITANIUM ALLOY PLATE PRODUCTION Russian patent published in 2008 - IPC C22F1/18 

FIELD: nonferrous metal industry.

SUBSTANCE: the invention relates to the nonferrous metal industry, in particular, to the heat and mechanical processing of the biphasic titanium alloy with increased fracture viscosity; it can also be used in the aircraft industry and in the machine industry. The slab is heated up to a temperature 60-120°C higher than the polymorphic transition temperature and preliminary rolling in the β-area is performed, with a total deformation grade of 30-90%. After that, the final rolling is performed in two stages in the α+β area, a total deformation grade of 60-75% at the rolling temperature 30-50°C lower than the polymorphic transition temperature. After that, two annealings are performed, the first annealing in the β-area, at a temperature 20-40°C higher than the polymorphic transition temperature, during 0.5-1 hour, and the final annealing, at a temperature of 710-750°C. As a result of the alloy processing, a secondary β-transited structure is formed, the intragranular constitution of which is characterized by the presence of the α-phase, which has the same orientation within the borders of individual fragment colonies. The obtained plates have a high level of fracture viscosity (K1c) while maintaining the other mechanic properties at a high level.

EFFECT: biphasic titanium alloy plates are produced with high level of fracture viscosity.

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