Abrasive blast modification of surfaces

Abstract

A metal surface treatment method wherein the surface ( 10 ) is simultaneously bombarded with a mixture of abrasive particles ( 4 ) and dopant particles ( 6 ) which are delivered at a velocity in the range of 50-250 m/sec, and thereby depositing the dopant material on the surface. Also provided is an article ( 8 ) having a surface treated by such a method.

1 . A metal surface treatment method wherein the surface is simultaneously bombarded with a mixture of abrasive particles and dopant particles which are delivered at a velocity in the range of 50-250 m/sec, and thereby depositing the dopant material on the surface. 
     
     
         2 . A method as claimed in  claim 1 , wherein the particles are delivered at a velocity in the range of 100-200 m/sec. 
     
     
         3 . A method as claimed in  claim 2 , wherein the particles are delivered at a velocity in the range of 120-180 m/sec. 
     
     
         4 . A method as claimed in  claim 1 , carried out at ambient temperature. 
     
     
         5 . A method as claimed in  claim 1 , wherein the abrasive particles have an irregular or angular morphology. 
     
     
         6 . A method as claimed in  claim 1 , wherein the dopant is directly chemically bonded to the metal surface without any intermediate oxide layer. 
     
     
         7 . A method as claimed in  claim 1 , wherein the dopant particles are agglomerated together on the metal surface. 
     
     
         8 . A method as claimed in  claim 1 , wherein the abrasive has a hardness greater than 6.0 on the Mohs scale. 
     
     
         9 . A method as claimed in  claim 1 , wherein the abrasive has a hardness of 8.0 or above on the Mohs scale. 
     
     
         10 . A method as claimed in  claim 1 , wherein the abrasive has a hardness at least 2 levels higher than that of the dopant on the Mohs scale. 
     
     
         11 . (canceled) 
     
     
         12 . A method as claimed in  claim 1 , wherein the dopant is a polymer and the abrasive has an average particle size in the range of 5-5000 microns. 
     
     
         13 . A method as claimed in  claim 12 , wherein the abrasive has an average particle size in the range of 5-1500 microns. 
     
     
         14 - 17 . (canceled) 
     
     
         18 . A method as claimed in  claim 1 , wherein the dopant is a polymer and the abrasive has an average particle size of greater than 300 microns. 
     
     
         19 . A method as claimed in  claim 1 , wherein the abrasive constitutes at least 60 wt % of the mixture of abrasive and dopant particles. 
     
     
         20 - 21 . (canceled) 
     
     
         22 . A method as claimed in  claim 1 , wherein the dopant is a non-polymeric material and the abrasive has an average particle size of less than 500 microns. 
     
     
         23 - 24 . (canceled) 
     
     
         25 . A method as claimed in  claim 22 , wherein the dopant constitutes at least 20 wt % of the mixture of abrasive and dopant particles. 
     
     
         26 - 27 . (canceled) 
     
     
         28 . A method as claimed in  claim 1 , wherein the dopant particles have an average particle size in the range of 1-100 microns. 
     
     
         29 . (canceled) 
     
     
         30 . A method as claimed in  claim 1 , wherein at least some of the dopant particles penetrate the metal surface and remain physically impregnated in the metal. 
     
     
         31 . A method as claimed in  claim 1 , further comprising applying an additional coating on top of the deposited dopant material. 
     
     
         32 . A method as claimed in  claim 31 , wherein the additional coating is applied through a bombardment technique selected from cold spray, peen plating or microblasting. 
     
     
         33 - 36 . (canceled)