Removing Method of Hard Coating Film

Abstract

A hard coating film is efficiently etched by a krypton ion beam of comparatively large mass, and then it is slowly etched by an argon ion beam of small mass. As a result, a coating film removing operation can be performed in a short time with suppressing an influence of the coating film removal on a tool base material (changes in shape and dimension) to the minimum. Since both krypton and argon are an inert gas, even upon the surface of the tool base material being exposed, the surface weakness by chemical erosion can be completely prevented. As a result, even when a hard coating film coated working tool is reproduced by re-coating the tool base material with the hard coating film, the hard coating film is coated by excellent adhesion strength.

1 - 6 . (canceled) 
   
   
       7 . A removing method of hard coating film from a main body of a hard coating film coated member, a surface of the main body being coated with the hard coating film composing of a metal carbide, a metal nitride, or a metal carbonitride in Group IIIb, IVa, Va, or VIa of the periodic table of the elements, or composing of a solid solution of these compounds the hard coating film being removed from the main body by irradiating an ion beam onto the hard coating film to etch the hard coating film, characterized by that:
 the etching is performed by irradiating the ion beam created using an inert gas as a working gas onto the hard coating film, the etching comprising steps of:   a first etching step of etching the hard coating film by irradiating the ion beam created using a first inert gas as a working gas onto the hard coating film; and   a second etching step of etching the hard coating film by irradiating the ion beam created after switching of working gas from the first inert gas to a second inert gas of which atomic weight is smaller than the first inert gas onto the hard coating film.   
   
   
       8 . The removing method of hard coating film according to  claim 7 , wherein the first etching step uses any one of radon, xenon, and krypton as the working gas, and the second etching step uses an argon gas as the working gas. 
   
   
       9 . The removing method of hard coating film according to  claim 7 , wherein the main body is made of a super-hard alloy. 
   
   
       10 . The removing method of hard coating film according to  claim 7 , wherein the hard coating film coated member is a hard coating film coated working tool in which at least a working part is coated with the hard coating film. 
   
   
       11 . The removing method of hard coating film according to  claim 7 , wherein during the etching by the ion beam, an emitting member of the ion beam and the hard coating film coated member are relatively moved. 
   
   
       12 . The removing method of hard coating film according to  claim 7 , wherein the etching by the ion beam is performed at a final stage of the hard coating film removal. 
   
   
       13 . The removing method of hard coating film according to  claim 7 , wherein the hard coating film has thickness of 1 μm to 5 μm. 
   
   
       14 . The removing method of hard coating film according to  claim 7 , wherein the first etching step uses the xenon gas, and the second etching step uses the krypton gas. 
   
   
       15 . The removing method of hard coating film according to  claim 9 , wherein the surface of the main body is roughened and/or formed with a foundation coating.