Microstructural characterization of arc-melted and directionally solidified near-eutectic molybdenum–silicon–boron alloys. (May 2021)

• Record Type: Journal Article
• Authors: Zhu, Linye; Ida, Shuntaro; Hasemann, Georg; Krüger, Manja; Yoshimi, Kyosuke
• Is Part Of: Intermetallics. Volume 132(2021)
• Publication Date: 2021-05
• Subjects: Directional solidification -- Intermetallics -- Microstructure -- Scanning electron microscopy; Intermetallic compounds -- Metallography -- Periodicals; Metallic glasses -- Periodicals; Composés intermétalliques -- Métallographie -- Périodiques; 669.94
• DOI: 10.1016/j.intermet.2021.107131
• Languages: English
• ISSNs: 0966-9795

Abstract

Abstract: Samples of near-eutectic Mo–Si–B alloys, with the nominal composition corresponding to the Moss + Mo3 Si + T2 eutectic area, were prepared by arc-melting or by crucible-free zone-melting methods (directional solidification). In the directionally solidified (DSed) alloy, the volume fraction of the Moss + Mo3 Si + T2 eutectic cells appeared to increase compared with that of arc-melted (AMed) alloy, and well-aligned and rod-shaped Moss and T2 phases were formed in a Mo3 Si matrix of the eutectic cells. In the AMed alloy, only the T2 phase showed a <100] preferential growth orientation along the solidification direction, whereas the Moss phase displayed no obvious preferred orientation. The Mo3 Si matrix showed a weak preference toward <001> growth along the solidification direction in the AMed alloy, and this became much stronger in the DSed alloy. Furthermore, the DSed alloy exhibited an apparent preferential growth orientation relationship of <001>Moss //<001>Mo3 Si//<100]T2 along the solidification direction. However, no specific atomic structures were observed at the interfaces, indicating that the three phases grew independently from the liquid without the formation of any habit interface during solidification. Graphical abstract: Image 1 Highlights: The microstructural evolution of directionally solidified near-eutectic Mo–Si–B alloy was investigated. Directional solidification increased the volume fraction of the Moss + Mo3 Si + T2 eutectic and improved its alignment. The directionally solidified alloy exhibited the growth of <001>Moss //<001>Mo3 Si//<100]T2 along solidification direction. Moss, Mo3 Si, and T2 phases in the directionally solidified alloy grew independently without forming any habit interface.