| 摘要 |
PURPOSE:To obtain a hard exterior part for time piece, having improved wear resistance and corrosion resistance, by covering the surface of the case of a time piece which is molded into a given shape with a hard TaC layer formed by flame coating. CONSTITUTION:An inexpensive and of low-hardness material, e.g., stainless steel, is molded into the case of a time piece, and then molten TaC is sprayed on the surface of the case by a spray gun by a plasma flame coating method, where the temperature of the case is 200 deg.C or less and little or no thermal deformation occurs thereat. Thus, a 10-300mum-thick TaC film is formed on the surface of the case and the hardness of the surface layer becomes Hv 600-2,000. As a result, a golden- colored, scratch-proof, and crack-proof case for a time piece even when fallen, having a high value added, can be obtained. |
