Material for thermal spraying and production method thereof, method for thermal spraying, and product of thermal spraying

Abstract

Thermal spraying may be readily carried out using fine particles which were difficult to be handled in the conventional art by using particles of a resin containing the fine particles of a ceramic or a metal as a material for thermal spraying. To produce a material for thermal spraying, the fine particles are dispersed in a liquid resin, and a cured material obtained by curing the mixture is pulverized to obtain a material for thermal spraying which contains particles having a particle diameter within a target particle diameter range, and these operations are repeated. In the second or later time production of a material for thermal spraying, over-pulverized particles which were obtained in a completed pulverization step of a cured material and have a particle diameter below the target particle diameter range are also added to a liquid resin and are disperse in the step for dispersing fine particles in a liquid resin. Accordingly, the yield rate of a material for thermal spraying produced from the fine particles and the resin may be improved by recycling the over-pulverized particles which are too small to be used as a material for thermal spraying in a next time or later production of a material for thermal spraying.

1 . A method for producing a material for thermal spraying, used for plasma thermal spraying, flame thermal spraying, or laser thermal spraying, the method comprising the steps of:
 a) dispersing fine particles of a ceramic or a metal in a liquid resin;   b) pulverizing a cured material from a mixture obtained in the step a) to obtain a material for thermal spraying having a particle diameter which is larger than that of the fine particles and is within a predetermined target particle diameter range; and   c) repeating the step a) and step b),   wherein over-pulverized particles having a particle diameter below the target particle diameter range obtained when the cured material is pulverized in a completed step b) are also added to the liquid resin and are dispersed in a second or later time step a).   
     
     
         2 . The method for producing a material for thermal spraying according to  claim 1 , wherein the over-pulverized particles are added to the liquid resin in a second or later time step a) after the fine particles are dispersed in the liquid resin. 
     
     
         3 . The method for producing a material for thermal spraying according to  claim 1 , wherein time for pulverizing the cured material in the step b) is determined in advance based on percentages of the material for thermal spraying and the over-pulverized particles obtained in a step b). 
     
     
         4 . The method for producing a material for thermal spraying according to  claim 1 , wherein, in the step b), the material for thermal spraying is obtained using a sieve from the cured material after the cured material is pulverized, and
 wherein the over-pulverized particles added to the liquid resin in a second or later time step a) are separated from the material for thermal spraying by a sieve in a completed step b) and are aggregated.   
     
     
         5 . The method for producing a material for thermal spraying according to  claim 1 , wherein the over-pulverized particles added to the liquid resin in the second or later time step a) are all of the over-pulverized particles obtained in a previous step b). 
     
     
         6 . The method for producing a material for thermal spraying according to  claim 1 , wherein the fine particles have an average particle diameter of not less than 25 nm and not more than 1000 nm when the average particle diameter is measured by a laser diffraction scattering method or a dynamic-light-scattering method. 
     
     
         7 . The method for producing a material for thermal spraying according to  claim 1 , wherein the liquid resin has room-temperature curing properties and wherein the step a) comprises the steps of:
 a1) stirring an intermediate substance obtained by adding the fine particles to the liquid resin for a predetermined unit stirring time;   a2) cooling the intermediate substance after the step a1); and   a3) repeating the step a1) and the step a2) until a total stirring time of the intermediate substance amounts to not less than a required stirring time.   
     
     
         8 . A material for thermal spraying, wherein the material is produced by the method according to  claim 1  and is used for plasma thermal spraying, flame thermal spraying, or laser thermal spraying. 
     
     
         9 . A method for thermal spraying comprising the steps of:
 d) preparing a material for thermal spraying by the method according to  claim 1 ; and   e) carrying out plasma thermal spraying, flame thermal spraying, or laser thermal spraying using the material for thermal spraying to fuse the fine particles by heat and thereby form a coating on a substrate.   
     
     
         10 . The method for thermal spraying comprising the steps of:
 d) preparing a material for thermal spraying by the method according to  claim 1 ;   e) carrying out plasma thermal spraying, flame thermal spraying, or laser thermal spraying using the material for thermal spraying to fuse the fine particles by heat and thereby form a coating on a substrate;   f) preparing another material for thermal spraying, wherein the other material is produced by the method according to  claim 1  and contains other fine particles which are formed from a raw material different from that of the fine particles dispersed in the step a);   g) carrying out plasma thermal spraying, flame thermal spraying, or laser thermal spraying using the other material for thermal spraying after the step e) to fuse the other fine particles and thereby form another coating on the coating formed in the step e).   
     
     
         11 . A product obtained by thermal spraying, comprising a substrate and a coating formed on the substrate by the method for thermal spraying according to  claim 9 .