Vapor deposition processes are not "new." These techniques have been used for years to produce thin film deposits such as those that are required in integrated circuit chips or for optical coatings. Coatings produced by vapor deposition techniques for resistance to wear in metal cutting applications came into common use approximately 7 years ago. About that time twist drills, threading taps, and other commonly used cutting tools started to be produced in significant quantities with yellow, titanium nitride coatings. Such coatings promoted extended tool life and improved productivity because higher metal removal rates could be achieved with TiN coated tools during metal cutting. The yellow color of TiN and (TiZr)N deposits suggests that they might be used in decorative applications where a pleasing appearance as well as functional performance is required. In fact, processes are available that allow a thin film of gold or gold alloy to be deposited onto a TiN substrate to achieve an ultimate degree of control over the final color of the deposit.

Author: John McCloskey