Formation of the Ti2Alc Max-Phase in a Hydride Cycle From a Mixture of Titanium and Aluminum Carbohydride Powders

• Published in: Russian journal of physical chemistry. B 2022, Vol.16 (1), p.76-83
• Main Authors: Dolukhanyan, S. K., Aleksanyan, A. G., Ter-Galstyan, O. P., Muradyan, G. N., Mnatsakanyan, N. L., Asatryan, K. V., Mnatsakanyan, A. S.
• Format: Article
• Language: English
• Subjects: Aluminum; Chemistry; Chemistry and Materials Science; Differential thermal analysis; Energy consumption; Heating; Hydrides; Materials science; Phase composition; Physical Chemistry; Physical Methods for Studying Chemical Reactions; Solid phases; Temperature effects; Titanium
• ISSN: 1990-7931; 1990-7923
• DOI: 10.1134/S1990793122010043

The creation and development of new methods and technologies for obtaining MAX-phases, promising materials based on oxygen-free ceramics, which are in demand in modern materials science as structural materials, is an urgent task. The existing methods of obtaining them are rather complicated, energy-intensive, and multistage. It is of scientific and practical interest to develop viable commercial proposals that cost less and make it possible to manufacture MAX-phases in larger quantities. This paper presents the results of studies of the processes of the formation of the Ti 2 AlC MAX-phase in the hydride cycle (HC) using titanium carbohydrides TiC 0.45 H 1.07–1.17 (the content of H 2 is 1.97–2.17 wt %) with an HCP structure and TiC 0.5 H 0.22–0.73 (the content of H 2 is 0.44–1.48 wt %) with an FCC structure as the initial components The reaction TiC 0.45–0.5 H 0.22–1.17 + 0.5Al → Ti 2 AlC + H 2 ↑ is studied. The task of this study is to establish the effect of temperatures and the heating time on the phase composition and structure of the Ti 2 AlC MAX-phase. For the certification of samples, the following set of analysis methods is used: chemical, differential thermal, and X-ray phase. The microstructure of the samples is investigated on the scanning electron microscope SEM Prisma E. As a result of the research on the HC, a single-phase Ti 2 AlC MAX-phase is synthesized ( a = 3.0553 Å, c = 13.6459 Å, c / a = 4.466, symmetry group P 6 3 / mmc ). The Ti 2 AlC MAX-phase is formed in the HC by the solid-phase mechanism, in one technological stage, during heating at 1000°С for 0.5–1 h. The advantages of the HC method in the synthesis of the Ti 2 AlC MAX-phases regarding traditional methods, which allow us to simplify the technological process, reduce energy consumption, and improve quality, are shown.