Evaluation of growth behaviour of vanadium carbides-reinforced iron-based surface compound layer by in-situ reaction

Abstract

The growth of vanadium carbide reinforced iron substrate surface compound layers are investigated, where the compound coatings were fabricated by in situ synthesis process at 950 °C, 1000 °C and 1050 °C in 1–5 h, respectively. A detailed characterization about the microstructural change of compound layer is given by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The obtained vanadium carbide compound layers are composed of V2C and V8C7. V2C and V8C7 have different microstructures and crystal orientations. The thickness of the vanadium carbide layer ranges from 16.62 ± 0.16 μm to 81.47 ± 0.63 μm in different process conditions. Growth kinetics of the layer follows the parabolic rules and the calculated activation energy value is Q=415.7KJ/mol. Both the heating treatment temperature and the holding time constantly influence on the microstructure and growth behaviour of the vanadium carbide compund layer.