Decorative parts

Abstract

Abstract PURPOSE:To produce an ornamental member resembling stainless steel material in color tone and free from scratches at a low cost by forming a hard film consisting of a lower layer composed principally of metallic chromium and an upper layer composed principally of chromium carbonitride on a substrate. CONSTITUTION:A substrate 1 composed of SUS 304 is cleaned in a vacuum tank, and then, the inside of the vacuum tank is regulated to about 1X10<-4>Torr and a lower layer 2 composed principally of metallic chromium is formed on the substrate 1 by an ion plating method. Subsequently, nitrogen gas and acetylene gas are rapidly introduced and an upper layer 3 composed principally of chromium carbonitride is formed to about 0.15-3.0mu thickness. By this method, an ornamental member in which the surface of the upper layer 3 has a color tone resembling, very closely, that of stainless steel where L*, a*, and b* satisfy the relations in 65%<=L*<=90%, -3<=a*<=5, and -5<=b*<=10, respectively, in the (CIE1976)L*, a*, and b* color space specified by JIS Z8105-2068 and which has wear resistance, scratch resistance, high adhesive strength, and high hardness can be inexpensively obtained. This member is useful, e.g., for outer ornament parts for watch.

Inventors

• 👤 Akira Uchiyama
• 👤 明 内山

Bibliographic Details