Effect of Alloying on the Occurrence of Phase Transformations During Continuous Heating of Quenched Model Titanium Pseudo-Alpha-Alloys

Abstract

The effect of alloying of model alloys based on a Ti – 10Al binary alloy with additives of 1% molybdenum and niobium, 3% tin, and 4% zirconium quenched from the β-range on the formation of structure, martensite lattice parameters, hardness, and contact modulus of elasticity is studied using the methods of diffraction analysis, microindentation, and Rockwell hardness measurements. The method of synchronous thermal analysis is used to determine the stages of the phase transformations (α′→ α + α₂ + β, α₂ → α, α + β → β) and the development of oxidation in the quenched model alloys under continuous heating to 1200°C. It is shown that complex alloying of the Ti – 10Al alloy with Mo, Nb, Sn and Zr promotes (1) occurrence of processes of decomposition of α′-martensite at higher temperatures, (2) lowering of the temperature range of the α + β → β transformation and (3) convergence of the temperature intervals of the α₂ → β and α + β → β transformations up to their overlapping.