| 摘要 |
PURPOSE:To provide very high scratch resistance to a metallic case for a wrist watch by successively plating the case with an Ni-W alloy and Pd, coating the plated case with TiN by PVD, and age-hardening the formed Ni-W alloy layer at the same time. CONSTITUTION:The metallic case of stainless steel, brass, German silver or the like for the wrist watch is successively plated with the Ni-W alloy to about 40mum thickness and with Pd to about 0.5mum thickness. The plated case is coated with TiN to about 1mum thickness by PVD at 400-600 deg.C, and at the same time, the formed Ni-W alloy layer is age-hardened. Thus, 1,200-1,500 Vickers microhardness measured under 300g load is attained. |
