Self-Propagiating High-Temperature Synthesis in Ti-Al-Mn
P. A. Lazarev, M. L. Busurina, A. E. Sychev
Merzhanov Institute of Structural Macrokinetics and Materials Science, Russian Academy of Sciences, Chernogolovka, Russia
Keywords: intermetallic compounds, self-propagating high-temperature synthesis, microstructure, Al-Ti-Mn system, X-ray diffraction analysis
Abstract
Alloys based on the Ti-Al-Mn ternary system are among the most important in the development of doped titanium alloys for various purposes. In this work, an alloy made of 42.9 % of Ti, 24.3 % of Al, and 32.8 % of Mn (by wt.) is obtained via self-propagating high-temperature synthesis (SHS) during a thermal explosion. X-ray diffraction analysis shows that the final synthesis product containsa cubic TiMn0.32Al2.68 phase, a hexagonal TiMn0.755Al1.246 phase, and a binary Mn3Al2 phase. The porosity of synthesized samples is rather high ≈41 %), and they contain many pores (up to 300 ÷ 400 μm). Phase formation may be due to the fact that the maximum temperature reached during the combustion of this system in the SHS process is insufficient for complete interaction with the formation of a Mn2Ti intermetallic phase and the dissolution of aluminum Al in it with the formation of a solid solution (Mn, Al)2Ti. This promotes the formation of intermediate intermetallic phases, which can be in equilibrium with the liquid phase up to a melting point of titanium.
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