Enhancement of self-sustaining reaction by mechanical activation: case of an FeSi system

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 1999-05, Vol.264 (1), p.94-107
• Main Authors: Gras, C, Gaffet, E, Bernard, F, Niepce, J.C
• Format: Article
• Language: English
• Subjects: Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; FeSi; FeSi2; High energy ball-milling; Infrared thermography; Materials science; Materials synthesis; materials processing; Mechanical activation; Nanostructured powders; Physics; Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation; Self-propagating high-temperature synthesis; Time resolved X-ray diffraction
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/S0921-5093(98)01108-3

Mechanical high energy ball milling of an Fe+2Si elemental powders mixture was used to activate a self sustaining combustion reaction or so-called self-propagating high-temperature synthesis (SHS) to form iron disilicide, a reaction for which the thermodynamic criterion is not favorable. A complete characterization of the milled powders before reaction was performed with energy dispersive X-ray spectrometry, specific surface measurements and X-ray diffraction profile analysis. Thermal and structural information describing the combustion front initiated by heating up a sample to 400°C in a Fe–Si system is communicated. In order to isolate the phases involved in the gasless reaction, a time-resolved X-ray diffraction experiment was designed to study in situ the formation of silicide phases (FeSi and β-FeSi 2) produced by the new process called MASHS (mechanically activated self-propagating high-temperature synthesis).