Boron-doped diamond coating and diamond-coated tool

Abstract

A boron-doped diamond coating that is to be disposed on a surface of a body includes a plurality of diamond microcrystal whose crystal grain diameter is substantially not larger than 2 μm, wherein the diamond microcrystal is doped with boron.

1 . A boron-doped diamond coating that is to be disposed on a surface of a body comprising: 
 a plurality of diamond microcrystal whose crystal grain diameter is substantially not larger than 2 μm,    wherein the diamond microcrystal is doped with boron.    
   
   
       2 . The boron-doped diamond coating according to  claim 1 , wherein each crystal grain diameter of at least not less than 80% of the number of the diamond microcrystals is not larger than 2 μm.  
   
   
       3 . The boron-doped diamond coating according to  claim 1 , wherein the boron-doped diamond coating is doped with boron in a ratio of 0.05-2.0 atomic % of boron.  
   
   
       4 . The boron-doped diamond coating according to  claim 3 , wherein a layer of boron oxide is formed on a surface of the boron-doped diamond coating when the surface is oxidized.  
   
   
       5 . The boron-doped diamond coating according to  claim 1 , wherein a maximum height Rz of the boron-doped diamond coating is not larger than 0.7 μm.  
   
   
       6 . The boron-doped diamond coating according to  claim 1 , wherein a thickness of the boron-doped diamond coating is in a range of 5-25 μm.  
   
   
       7 . The boron-doped diamond coating according to  claim 1 , wherein the body is made of cemented carbide.  
   
   
       8 . The boron-doped diamond coating according to  claim 1 , wherein the body is made of high-speed steel.  
   
   
       9 . A diamond-coated tool comprising: 
 a main body having a surface; and    the boron-doped diamond coating defined in  claim 1 ,    wherein the boron-doped diamond coating is disposed on the surface of the main body.    
   
   
       10 . The diamond-coated tool according to  claim 9 , wherein the diamond-coated tool is an end mill.  
   
   
       11 . The diamond-coated tool according to  claim 9 , wherein the diamond-coated tool is a turning tool.  
   
   
       12 . The diamond-coated tool according to  claim 9 , wherein the diamond-coated tool is a tap.  
   
   
       13 . The diamond-coated tool according to  claim 9 , wherein the diamond-coated tool is a drill.