ОСОБЕННОСТИ ФОРМИРОВАНИЯ β-СПЛАВОВ СИСТЕМЫ Ti-Nb МЕХАНИЧЕСКИМ СПЛАВЛЕНИЕМ В ВЫСОКОЭНЕРГЕТИЧЕСКОЙ ШАРОВОЙ МЕЛЬНИЦЕ

Abstract

Using the scanning electron microscopy, energy-dispersive microanalysis, and the X-ray diffraction analysis methods, the authors studied the structure and phase composition of Ti-Nb system powders produced in the result of mechanical mixing and alloying of components in the AGO-2C high-energy planetary ball mill. Based on this study and the study of reference data about physical and mechanical properties of these powders, the authors developed the phenomenological model of Ti and Nb interaction in the process of mechanical alloying. The powders were mixed in the ratios of Ti-40 mas % Nb and Ti-50 mas % Nb during 5, 10, 15, 20 and 25 minutes in the mill water-cooled vial. Depending on the treatment time, the shape, size, particles surface morphology, and the powders phase composition are changed. When changing the mixing time from 5 to 20 minutes, the particles are formed, which size varies in the range of 2–100 µm. When mixing during 25 minutes, the powder is granulated. In the process of mixing and alloying, the mechanocomposite consisting of two phases’ grains – the supersaturated solid solution of α-Ti and β-TiNb is formed. When mixing during 20 minutes, Ti-40 mas % Nb alloy components dissolved completely into each other and one β-TiNb non-equilibrium phase is formed. When mixing Ti-45 mas % Nb powder, the single-phase state is achieved in 15 minutes. The proposed phenomenological model of the process of Ti and Nb mechanical alloying involves two stages of initial components interaction and the β-TiNb metastable solid solution formation. Producing of Ti-Nb system single-phase alloys using mechanical alloying and understanding the principles of their formation expands the feasibility of application of these materials for the production of medical implants.