Method for producing silicon nitride based member coated with film of diamond
AssigneeNgk Spark Plug Co., Ltd.
InventorsSatoshi Iio, Masakazu Watanabe
Life of this patent
Estimating the term…
Abstract
Method for coating a substrate formed of a sintered silicon nitride based material with a film of diamond by a gas phase synthesis technique including a first step of applying a film having a thickness of 0.5 to 2.0 .mu.m at a temperature not higher than a temperature at which grain boundary components of the substrate volatilize, and a second step of synthesizing the film of diamond-and-the-like to a thickness of 5 to 100 .mu.at a temperature which expedites synthesis of the film of diamond.
Claims23
A method for coating a substrate of a cutting tool formed of a silicon nitride based material with a diamond film by a gas phase synthesis technique comprising
- providing a substrate of a sintered silicon nitride based material having grain boundary components which volatilize at a lower temperature than silicon nitride;
- a first step of applying said diamond film at a temperature less than a temperature at which the grain boundary components of said substrate volatilize, to a thickness which is sufficient to suppress volatilization of elements constituting a grain boundary phase during a subsequent step, and
- a second step of synthesizing said diamond film at a temperature which expedites synthesis of said diamond film to increase the thickness.
Dependencies are inferred from the claim text.