Corrosion-Resistant Member and Method for Manufacture Thereof

Abstract

A corrosion-resistant member used in a corrosive environment includes a substrate, and a ceramic sprayed film, which covers a part or all of the substrate surface and has relative density of 80% or greater. Maximum diameter of voids existing in the ceramic sprayed film surface is 25 μm or less. This corrosion-resistant member is obtained by using Y 2 O 3 as a material having a bulk density of at least 1.5 g/cm 3 and dried to a moisture content of 1 mass percent or less and spraying plasma on the substrate with an output power of 40 to 110 kW by a spraying device including two anode torches.

1 . A corrosion-resistant member used in a corrosive environment, the corrosion-resistant member comprising 
 a substrate and a ceramic sprayed film, which covers a part or all of the substrate surface and has a relative density of 80% or greater,    wherein the ceramic sprayed film has a thickness of 50 to 500 μm, and a surface prepared such that voids existing therein have a maximum diameter of 25 μm or less.    
   
   
       2 . The corrosion-resistant member of  claim 1 , wherein the ceramic sprayed film is a film made of Y 2 O 3 , and has an etching rate of 5 nm/min or less when plasma etching is performed under conditions of a flow rate of 50 mL/min, an output power of 1,000 W, and a pressure of 6.7 Pa using a mixed gas made of 80% CF 4  and 20% O 2  by a parallel plate type RIE apparatus with inter-electrode gap of 100 mm.  
   
   
       3 . The corrosion-resistant member of  claim 2 , wherein the corrosion-resistant member is obtained by using Y 2 O 3  having a bulk density of at least 1.5 g/cm 3  and a moisture content of 1 mass percent or less as material for the ceramic sprayed film and spraying plasma on the substrate with an output power of 40 to 110 kW by a spraying device including two anode torches.  
   
   
       4 . The corrosion-resistant member of  claim 1 , wherein the ceramic sprayed film is a film made of Al 2 O 3 , and has an etching rate of 20 nm/min or less when plasma etching is performed under conditions of a flow rate of 50 mL/min, an output power of 1,000 W, and a pressure of 6.7 Pa using a mixed gas made of 80% CF 4  and 20% O 2  by a parallel plate type RIE apparatus with inter-electrode gap of 100 mm.  
   
   
       5 . The corrosion-resistant member of  claim 4 , wherein the corrosion-resistant member is obtained by using Al 2 O 3  having a bulk density of at least 1.0 g/cm 3  and a moisture content of 1 mass percent or less as material for the ceramic sprayed film and spraying plasma on the substrate with an output power of 40 to 110 kW by a spraying device including two anode torches.  
   
   
       6 . A method for manufacture of a corrosion-resistant member by covering a substrate surface with a Y 2 O 3  film through plasma thermal spraying, the method comprising: 
 a drying step of drying material having a bulk density of at least 1.5 g/cm 3  until a moisture content is 1 percent or less by mass; and    a plasma thermal spraying step of spraying the material after drying on a substrate surface with an output power of 40 to 110 kW by a spraying device including two anode torches, and forming a Y 2 O 3  film having a relative density of 80% or greater, a thickness of 50 to 500 μm, and a surface prepared such that voids existing therein have a maximum diameter of 25 μm or less.    
   
   
       7 . A method for manufacture of a corrosion-resistant member by covering a substrate surface with an Al 2 O 3  film through plasma thermal spraying, the method comprising: 
 a drying step of drying material having a bulk density of at least 1.0 g/cm 3  until a moisture content is 1 percent or less by mass; and    a plasma thermal spraying step of spraying the material after drying on a substrate surface with an output power of 40 to 110 kW by a spraying-device including two anode torches, and forming an Al 2 O 3  film having a relative density of 80% or greater, a thickness of 50 to 500 μm, and a surface prepared such that voids existing therein have a maximum diameter of 25 μm or less.