Special Features of Al9Mn3Si g-Phase Formation During High-Temperature Synthesis in Al-Mn-Si: Combustion, Structurization, and Phase Formation
A. O. Sivakova1, P. A. Lazarev1, O. D. Boyarchenko1, A. E. Sychev1, G. A. Sychev2
1Merzhanov Institute of Structural Macrokinetics and Materials Science, Russian Academy of Sciences, Chernogolovka, Russia
2Joint Institute for High Temperatures (JIHT), Russian Academy of Sciences, Moscow, Russia
Keywords: self-propagating high-temperature synthesis, combustion, Al-Mn-Si, microstructure, intermetallic alloy, solid solution
Abstract
This paper is devoted to the preparation of Al-Mn-Si-based compounds with different Si contents (0, 5, 10, and 15 at.%) using self-propagating high-temperature synthesis (SHS). This method is used for the first time to obtain the Al9Mn3Si γ-phase with a hexagonal crystal lattice (P63/mmc space group) as part of a synthesized alloy with a content of 15 at.% of Si in the initial mixture. The X-ray diffraction analysis of the synthesized alloys from mixtures with a silicon content of 5-10 at.% also shows the presence of γ2-Al8Mn5 (trigonal, R3m space group) and MnSi (cubic, Pm-3m space group) phases. The phase formation of intermediate compounds at silicon content in a mixture below 15 at. % may be associated with combustion temperature, which is insufficient for complete interaction of the system components. Synthesized alloys are characterized by a porous structure with pore size up to 20 μm and a grain size in the pore space of 10-90 μm.
|
