| 摘要 |
PURPOSE:To improve abrasion resistance, corrosion resistance and diversification of color tones by carburizing, nitriding or carbonitriding the side of a watch case and a band made of stainless steel then coating the carbide, nitride or carbonitride of Ti thereon and further coating Al2O3 or TaC thereon. CONSTITUTION:The watch cases or bands made of stainless steel are heated in an NH3 gas atmosphere to 500 deg.C, whereby the surfaces are nitrided. Or they are heated to 800 deg.C in a gaseous CO, whereby they are carburized or carbonitrided. Next, they are heated to 1,000 deg.C in mixed gases of TiCl2 gas, H2 gas and N2 gas or CH4 gas, so that the coating layer of the carbide, nitride or carbonitride of Ti is formed. Finally, an amorphous Al2O3 film is formed by an anodic oxidation method or the like, after which it is crystallized by heating or is heated in mixed atmospheres of TaCl4 gas, H2 gas, CH4 gas, etc., whereby a TaC layer is formed. The total thickness of these films is kept at 0.5-5mu. |
