Chromium silicide-based composites fabricated via solid-state reactions: Phase development, oxidation behavior and electrical properties at high-temperatures

JOURNAL OF ALLOYS AND COMPOUNDS

卷:769

Article

Yakaboylu, Gunes A.¹  Sabolsky, Katarzyna¹  Sabolsky, Edward M.¹ 

[1] West Virginia Univ, Dept Mech & Aerosp Engn, 395 Evansdale Dr, Morgantown, WV 26506 USA

关键词: Composite materials;    Intermetallics;    Solid state reactions;    Electrical transport;    Phase transitions;    Microstructure;   

DOI  :  10.1016/j.jallcom.2018.07.253

来源: Elsevier

【 摘 要 】

The chromium silicide-based electroconductive composites were fabricated by solid-state sintering of chromium silicide and chromium oxide powders at 1370 degrees C in argon. The final densified composites were composed of various solid solution and silicide phases (e.g. Cr3Si, Cr5Si3) and silica, depending on the starting silicide/oxide volume ratio ranging from 0.67 to 9.0. Major phases were found to be homogeneously distributed within the metastable (cristobalite) and/or amorphous silica grain boundary phase. The controlled oxidation experiments revealed excellent oxidation resistance at 50 degrees-870 degrees C, where low-level oxidation was observed. The composites all displayed a metallic-type electrical conductivity due to the presence of the Cr3Si, Cr5Si3 and CrSi as the major conductive silicide phases. Their electrical conductivities ranged from 42.1 to 213.7 S/cm at 1000 degrees C. High-temperature annealing of the composites resulted in phase and microstructural changes, which further improved their high-temperature oxidation resistance and electrical transport properties. (C) 2018 Elsevier B.V. All rights reserved.

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