Y
A member is obtained by forming a Y 2 O 3 black spray coating on a surface of a substrate or covering the surface of the substrate with a Y 2 O 3 black spray coating through an undercoat or a middle layer. This coating has good heat characteristics and is good in the resistance to damaging through a high hardness. The Y 2 O 3 black spray coating is produced by subjecting white Y 2 O 3 powdery material to a plasma spraying in an inert gas atmosphere containing substantially no oxygen or by forming a Y 2 O 3 white spray coating and then irradiating an electron beam or a laser beam to this coating to melt at least a part of the white coating under heating to thereby smoothen denseness and blacken the surface of the coating.
1. A Y 2 O 3 spray-coated member characterized by covering a surface of a substrate with a Y 2 O 3 black spray coating, wherein the Y 2 O 3 black spray coating is generated by an electron beam process.
2. A Y 2 O 3 spray-coated member according to claim 1 , wherein an undercoat made of a metal coating is disposed beneath a Y 2 O 3 black spray coating.
3. A Y 2 O 3 spray-coated member according to claim 2 , wherein a middle layer is disposed between an undercoat made of a metal coating and a Y 2 O 3 black spray coating as a top coat.
4. A Y 2 O 3 spray-coated member according to claim 2 , wherein the undercoat is a metal coating made of at least one metal or alloy selected from Ni and its alloy, W and its alloy, Mo and its alloy, Ti and its alloy, Al and its alloy, and Mg alloy at a thickness of 50-500 μm.
5. A Y 2 O 3 spray-coated member according to claim 3 , wherein the middle layer is made of a coating of Al 2 O 3 , a double oxide of Al 2 O 3 and Y 2 O 3 , a solid solution or a mixture thereof.
6. A Y 2 O 3 spray-coated member according to claim 1 , wherein the Y 2 O 3 black spray coating is obtained by forming a Y 2 O 3 re-molten layer having a thickness of less than 30 μm and a blackened Y 2 O 3 layer on a surface of the Y 2 O 3 spray coating.
7. A Y 2 O 3 spray-coated member according to claim 1 , wherein the Y 2 O 3 black spray coating is constituted with a layer in which Y 2 O 3 particles blackened on an outer peripheral portion or an inside of Y 2 O 3 particle constituting the spray coating are deposited to a thickness of about 50-2000 μm.
8. A method of producing a Y 2 O 3 spray-coated member, characterized in that a white Y 2 O 3 powdery material is sprayed directly on a surface of a substrate or on an undercoat applied onto the surface of the substrate to form a Y 2 O 3 white spray coating, and then an electron beam is irradiated under a low pressure or in an inert gas atmosphere under a low pressure to form a blackened Y 2 O 3 layer on the surface of the Y 2 O 3 white spray coating.
9. A method of producing a Y 2 O 3 spray-coated member according to claim 8 , wherein the undercoat made of a metal coating is disposed beneath the Y 2 O 3 black spray coating.
10. A method of producing a Y 2 O 3 spray-coated member according to claim 8 , wherein a middle layer is disposed between the undercoat made of a metal coating and the Y 2 O 3 black spray coating formed as a top coat.
11. A method of producing a Y 2 O 3 spray-coated member according to claim 8 , wherein the inert gas atmosphere is an atmosphere under a low pressure of 50-600 hPa.
12. A method of producing a Y 2 O 3 spray-coated member according to claim 8 , wherein the inert gas atmosphere includes an environment of a heat source for an atmosphere plasma spraying surrounded with a gas such as Ar, N 2 or the like so as not to penetrate air into the heat source.
13. A method of producing a Y 2 O 3 spray-coated member according to claim 10 , wherein the middle layer is made of a coating of Al 2 O 3 , a double oxide of Al 2 O 3 and Y 2 O 3 , a solid solution or a mixture thereof.
14. A method of producing a Y 2 O 3 spray-coated member according to claim 8 , wherein the Y 2 O 3 black spray coating is obtained by forming a Y 2 O 3 re-molten layer having a thickness of less than 30 μm and a blackened Y 2 O 3 layer on a surface of the Y 2 O 3 spray coating.
15. A method of producing a Y 2 O 3 spray-coated member according to claim 8 , wherein the Y 2 O 3 black spray coating is constituted with a layer in which Y 2 O 3 particles blackened on an outer peripheral portion or an inside of Y 2 O 3 particle constituting the spray coating are deposited to a thickness of about 50-2000 μm.