Covering member and method for manufacturing the same
A covering member has a hard film on the surface of a base material, wherein the hard film comprises a layer A selected from a nitride, a carbonitride, an oxynitride, and an oxycarbonitride of Cr or CrM; a metal layer which is formed on the outer surface side of the A layer and includes Cr, Ti, or W; and a layer B which is formed on the outer surface side of the metal layer and selected from a nitride, a carbonitride, an oxynitride, and an oxycarbonitride of Cr or CrM, and wherein M is one or two or more from a Group 4 metal, a Group 5 metal, a Group 6 metal of the periodic table, Al, Si, and B, and strain is introduced in the outer surface side of the metal layer.
1. A covering member having a hard film on a surface of a base material,
wherein the hard film includes a layer A selected from among a nitride, a carbonitride, an oxynitride, and an oxycarbonitride of Cr or CrM (M is one or two or more selected from among Group 4 metals, Group 5 metals, and Group 6 metals on the periodic table, Al, Si, and B),
a metal layer which is formed on an outer surface side of the layer A and contains Cr, Ti, or W, and
a layer B which is formed on the outer surface side of the metal layer and is selected from among a nitride, a carbonitride, an oxynitride, and an oxycarbonitride of Cr or CrM (M is one or two or more selected from among Group 4 metals, Group 5 metals, and Group 6 metals on the periodic table, Al, Si, and B), wherein the metal layer is between the layer A and the layer B, and
wherein strain is introduced into the outer surface side of the metal layer to form a strain area, the strain area is located at the outer surface side adjacent to the layer B.
2. The covering member according to claim 1 , wherein a second metal layer containing Cr, Ti, or W is provided on the outer surface side of the layer B.
3. The covering member according to claim 1 , wherein the thickness of at least one of the layer A and the layer B is 4 to 20 μm.
4. The covering member according to claim 3 , wherein the thickness of at least one of the layer A and the layer B is 6 μm or more.
5. A method for manufacturing a covering member having a hard film on a surface of a base material, comprising:
a first coating step in which a base material is coated with a layer A selected from among a nitride, a carbonitride, an oxynitride, and an oxycarbonitride of Cr or CrM (M is one or two or more selected from among Group 4 metals, Group 5 metals, and Group 6 metals on the periodic table, Al, Si, and B);
a metal layer coating step in which a metal layer containing Cr, Ti, or W is coated after the layer A is coated;
a metal layer modifying step in which strain is introduced into a surface layer of the metal layer after the metal layer is coated; and
a second coating step in which a layer B selected from among a nitride, a carbonitride, an oxynitride, and an oxycarbonitride of Cr or CrM (M is one or two or more selected from among Group 4 metals, Group 5 metals, and Group 6 metals on the periodic table, Al, Si, and B) is coated after the metal layer modifying step.
6. The method for manufacturing a covering member according to claim 5 , wherein the metal layer modifying step is metal ion bombardment using Cr ions or Ti ions.
7. The method for manufacturing a covering member according to claim 5 , wherein a polishing step of polishing a surface of the layer A is performed between the first coating step and the metal layer coating step.
8. The method for manufacturing a covering member according to claim 5 , wherein a second metal layer coating step in which a second metal layer containing Cr, Ti or W is coated is provided after the second coating step.