EFFECT OF ALLOYING PROPERTIES OF Ti-40Nb SYSTEM ALLOYS

Исследованы процессы распада метастабильной β-фазы в закаленных сплавах системы Ti-40Nb при старении 400 и 500 °С, установлены временные интервалы выделения вторых фаз (α и ω). Проанализировано влияние легирования на изменение структуры, фазового состава и свойств после закалки и старения.The processes of decomposition of the metastable β-phase in hardened alloys of the Ti-40Nb system upon aging at 400 and 500 °C have been studied, and the time intervals for the precipitation of the second phases (α and ω) have been established. The influence of alloying on changes in structure, phase composition and properties after hardening and aging is analyzed.Работа выполнена в рамках соглашения с Министерством науки и высшего образования № 075-03-2023-006 от 16.01.2023 (номер темы FEUZ-2023-0015)

FORMATION OF INTERMEDIATE PHASES AND THEIR INFLUENCE ON THE MICROSTRUCTURE IN METASTABLE BETA ALLOYS

Изучен процесс распада метастабильного β-твердого раствора в областях температур βα превращения в закаленных сплавах Ti – 14Mo и VST3553 в интервале температур старения от 200 до 550 °С. С использованием рентгеноструктурного фазового анализа, дифференциально сканирующей калориметрии и просвечивающей электронной микроскопии установлено наличие метастабильных ω и Оʺ-фаз в сплавах, закаленных из β-области. Выявлено, что O'- и/или Оʺ-фазы непрерывно связаны с выделением ω-фазы и являются переходными до температуры образования α-фазы – 500 °С.The process of decomposition of a metastable β-solid solution in the temperature range βα transformation in hardened Ti – 14Mo and VST3553 alloys in the aging temperature range from 200 to 550 °C has been studied. Using X-ray diffraction phase analysis, differential scanning calorimetry and transmission electron microscopy, the presence of metastable ω and Oʺ-phases in alloys quenched from the β region was established. It was revealed that the O'- and/or Oʺ-phases are continuously associated with the release of the ω-phase and are transitional up to the formation temperature of the α-phase – 500 °C.Работа выполнена в рамках соглашения с Министерством науки и высшего образования № 075-03-2023-006 от 16.01.2023 (номер темы FEUZ-2023-0015)

A Review—Additive Manufacturing of Intermetallic Alloys Based on Orthorhombic Titanium Aluminide Ti2AlNb

Titanium alloys based on orthorhombic titanium aluminide Ti2AlNb are promising refractory materials for aircraft engine parts in the operating temperature range from 600–700 °C. Parts made of Ti2AlNb-based alloys by traditional technologies, such as casting and metal forming, have not yet found wide application due to the sensitivity of processability and mechanical properties in chemical composition and microstructure compared with commercial solid-solution-based titanium alloys. In the last three decades, metal additive manufacturing (MAM) has attracted the attention of scientists and engineers for the production of intermetallic alloys based on Ti2AlNb. This review summarizes the recent achievements in the production of O-phase-based Ti alloys using MAM, including the analysis of the feedstock materials, technological processes, machines, microstructure, phase composition and mechanical properties. Powder bed fusion (PBF) and direct energy deposition (DED) are the most widely employed MAM processes to produce O-phase alloys. MAM provides fully dense, fine-grained material with a superior combination of mechanical properties at room temperature. Further research on MAM for the production of critical parts made of Ti2AlNb-based alloys can be focused on a detailed study of the influence of post-processing and chemical composition on the formation of the structure and mechanical properties, including cyclic loading, fracture toughness, and creep resistance