TABLEWARE AND METHOD FOR SURFACE TREATMENT THEREOF, SUBSTRATE HAVING HARD DECORATIVE COATING FILM AND METHOD FOR PRODUCTION THEREOF, AND CUTLERY

摘要

Tableware made of Ti or a Ti alloy having a hard surface layer formed thereon, characterized in that the hard surface layer comprises a first hardened layer (102) containing a solid solution having nitrogen and oxygen formed in a region from its surface to an desired depth and a second hardened layer (103) formed in a desired region being adjacent to and deeper than that of the first layer; a method for the surface treatment thereof comprising forming the above hard surface layer; and a substrate (100) having a hard decorative coating film which comprises Ti or a Ti alloy, has an internal hard layer (101) comprising the above first and second hardened layers in its surface part, and has a hard decorative coating film (23) formed on the surface of the internal hard layer.