Influence of Dy and Ho on the Phase Composition of the Ti-Al System Obtained by 'Hydride Technology'

• Published in: Materials 2022-12, Vol.15 (23), p.8584
• Main Authors: Karakchieva, Natalia, Artemenko, Alina, Sokolov, Sergei, Amelichkin, Ivan, Knyazev, Alexey, Vorozhtsov, Alexander, Abzaev, Yuri, Sachkov, Victor, Kurzina, Irina
• Format: Article
• Language: English
• Subjects: Aluminum; Chemical properties; Chemical synthesis; Crystallography; Energy; Hydrides; Intermetallic compounds; Mathematical analysis; Mechanical properties; Methods; Microhardness; Phase composition; Phase diagrams; Phases; Physical properties; Production processes; Radiation; Solids; Thermal properties; Titanium; Titanium alloys
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma15238584

The manuscript describes the phase composition, microstructure, some physical and mechanical properties of the Ti-Al system with addition of 2 at. % Dy (TAD) and Ho (TAH) obtained by "hydride technology". Phase diagrams for Ti-Al-Dy and Ti-Al-Ho at a temperature of 1150 °C and basic properties for ternary phases Dy₆Ti₄Al₄₃ and Ho₆Ti₄Al₄₃ were calculated. A crystallographic database of stable and quasistable structures of the known elemental composition was created in the USPEX-SIESTA software by means of an evolutionary code. The calculations show that adding REM leads to a significant stabilizing effect in each Ti-Al-Me (Me = Dy, Ho) system without exception. It has been established that the lattice energies of AlTi Ho and AlTi Dy are, respectively, equal to: EAl Ti Dy = -32,877.825 eV and EAl Ti Dy = -31,227.561 eV. In the synthesized Ti Al Ho compound, the main phases include Al-Ti, Al Ti and Al Ti Ho and the contributions to the theoretical intensity are equal to 44.83, 44.43 and 5.55%, respectively. Ti Al Dy is dominated by the Al-Ti, Al Ti and Al Ti Dy phases, whose contributions are equal to 65.04, 16.88 and 11.2%, respectively. The microhardness of TAD and TAN specimens is 1.61 ± 0.08 and 1.47 ± 0.07 GPa, respectively.