Substrate treatment method for portion to be coated

Abstract

A portion to be coated of a workpiece is subjected to substrate treatment by blasting to provide an anchor effect without leaving abrasive grains thereon. A substrate treatment method for a portion to be coated includes ejecting an elastic abrasive onto a portion to be coated of a workpiece to form irregularities with a predetermined surface roughness, thereby providing an anchor effect for a coating to be formed without causing the abrasive grains to be embedded in the surface of the workpiece. The elastic abrasive includes elastic carriers and abrasive grains, particularly, insulating abrasive grains, compounded and dispersed in the base material as an elastic body or carried on surfaces of the base materials by, for example, adhesion.

1 . A substrate treatment method for a portion to be coated,
 the method comprising;   ejecting an elastic abrasive onto a portion to be coated of a workpiece to form irregularities with a predetermined surface roughness,
 thereby providing an anchor effect for a coating to be formed on the portion to be coated without causing the abrasive grains to be embedded in the portion to be coated, 
 the elastic abrasive including base material as an elastic body and abrasive grains compounded and dispersed in the base material as an elastic body or carried on surfaces of the base material as an elastic body. 
   
   
   
       2 . The substrate treatment method for a portion to be coated according to  claim 1 , wherein;
 the surface roughness of the portion to be coated is controlled by changing the grain size of the abrasive grains in the elastic abrasive.   
   
   
       3 . The substrate treatment method for a portion to be coated according to  claim 1 , wherein;
 the surface roughness of the portion to be coated is controlled by changing conditions under which the elastic abrasive is ejected.   
   
   
       4 . The substrate treatment method for a portion to be coated according to  claim 1 , wherein;
 the abrasive grains are insulating and have an average grain size of 0.5 to 230 μm;   the elastic abrasive has an average grain size of 10 to 2,000 μm, the average grain size being selected on the basis of that of the abrasive grains; and   the elastic abrasive is ejected at an ejection pressure of 0.01 to 0.5 MPa, an ejection distance of 10 to 200 mm, and an incident angle of 30° to 75°.   
   
   
       5 . The substrate treatment method for a portion to be coated according to  claim 1 , wherein;
 there is no increase in an atom percent of silicon (Si) in the elastic abrasive.   
   
   
       6 . The substrate treatment method for a portion to be coated according to  claim 1 , wherein;
 the coating is formed by a method in which a voltage is applied to the workpiece excluding hard and brittle materials, and   the abrasive grains are formed of an insulating material such as carborundum, green carborundum, or alumina.   
   
   
       7 . The substrate treatment method for a portion to be coated according to  claim 4 , wherein;
 the abrasive grains are insulating and have an average grain size of 1.0 to 40 μm and   the abrasive grains are mixed and dispersed in the elastic abrasive made of rubber has an average grain size of 35 to 1,000 μm,   the average grain size being selected on the basis of that of the abrasive grains; and   the elastic abrasive is ejected at an ejection pressure of 0.02 to 0.5 MPa, an ejection distance of 50 to 100 mm.