Microstructural Characterization of Solid State Reaction Phase Formed During Sintering of Hexagonal Boron Nitride with Iron

Abstract

In the development of dry self-lubricating composites, not only solid lubricant particle size and distribution are important, but also the correct selection of the solid lubricant characteristics, which should be stable, i.e. not reactive, during the whole processing. In this work, Fe+9 vol% h-BN composites were produced by uniaxial cold compaction and sintering, for which a reaction between h-BN and iron was detected after sintering at 1,150°C. The reaction phase was characterized by optical and scanning electron microscopy and identified by X-ray diffraction and energy-dispersive X-ray spectroscopy. The newly formed phase had high hardness when compared with the iron matrix. The resulting composites presented a high friction coefficient and high wear.

Neural Network Approach for Characterizing Structural Transformations by X-Ray Absorption Fine Structure Spectroscopy

“…transmission X-ray experiment) and to prevent sample from oxidation and carbidization that plague most high temperature experiments with pure iron, the sample was gently packed between two BN pellets. Note that BN is thermally stable up to ca 3200 K [68], but reacts with iron at ca 1400 K [69].…”