Y. Hatanoa, M. Takamoria, K. Nogitab, K. Matsudac, S. Ikenoc, K. Watanabea
aHydrogen Isotope Research Center, Toyama University, Gofuku 3190, Toyama 930-8555, Japan
bDivision of Materials Engineering, The university of Queensland, Brisbane, Qld 4072, Australia
cDepartment of Material Systems Engineering and Life Science, Faculty of Engineering, Toyama University, Gofuku 3190, Toyama 930-8555, Japan
Plate-type speciments were cut from three different types of tungsten sheets fabricated under distinct rolling and heat treatment conditions in the directions parallel or perpendicular to the rolling planes. Amorphous carbon films were prepared by vacuum deposition on the specimen surfaces. Then, the specimens were heated at 1073 K in vacuum, and reaction products were analyzed by means of X-ray diffraction. The carbide formed was W2C and no peak of WC appeared. The growth rate of W2C was independent of the cutting directions of the specimens, although the grain boundary densities at the specimen surfaces were quite different. On the other hand, the rate of W2C growth was dependent on both reduction and heat treatment conditions, and a specimen with higher hardness showed a higher growth rate. By taking account of the observations by a transmission electron microscope, it was concluded that dislocations play important roles in W2C growth.