Coating and surface repair method

Abstract

A coating and surface repair method is provided. The method includes positioning a high velocity air fuel (HVAF) gun proximate to a damaged hardened steel surface and forming a ceramic metallic coating on the damaged hardened steel surface by executing an HVAF thermal spray process using the HVAF gun.

1 . A coating and surface repair method, comprising:
 positioning a high velocity air fuel (HVAF) gun proximate to a damaged hardened steel surface; and   forming a ceramic metallic coating on the damaged hardened steel surface by executing an HVAF thermal spray process using the HVAF gun.   
     
     
         2 . The coating and surface repair method according to  claim 1 , wherein the hardened steel surface comprises carburized steel. 
     
     
         3 . The coating and surface repair method according to  claim 1 , wherein the hardened steel surface comprises carburized steel, nitridized steel, borided steel, cyanided steel, carbo-nitrided steel or a combination thereof. 
     
     
         4 . The coating and surface repair method according to  claim 1 , wherein the damaged hardened steel surface is pitted. 
     
     
         5 . The coating and surface repair method according to  claim 1 , wherein the forming results in a repaired surface with fatigue and mechanical strength properties comparable to that of the original damaged hardened steel surface. 
     
     
         6 . The coating and surface repair method according to  claim 1 , wherein the damaged hardened steel surface has defects of sizes between 0.005-0.040 inches in diameter and depth. 
     
     
         7 . The coating and surface repair method according to  claim 1 , wherein the executing of the thermal spray process comprises maintaining combustion temperatures within a range of 1900-2300° C. 
     
     
         8 . The coating and surface repair method according to  claim 1 , wherein the ceramic metallic coating comprises a Tungsten-Carbide (WC) material. 
     
     
         9 . The coating and surface repair method according to  claim 1 , wherein the ceramic metallic coating comprises a Tungsten-Carbide Cobalt (WC/Co) material. 
     
     
         10 . The coating and surface repair method according to  claim 1 , wherein the ceramic metallic coating comprises a Tungsten-Carbide Cobalt-Chromium (WC/Co—Cr) material. 
     
     
         11 . A coating and surface repair method, comprising:
 positioning a high velocity air fuel (HVAF) gun proximate to a carburized steel surface exhibiting pitting damage;   executing an HVAF thermal spray process using the HVAF gun with respect to the carburized steel surface; and   forming a ceramic metallic coating comprising a Tungsten-Carbide (WC) material on the carburized steel surface as a result of the executing of the HVAF thermal spray process.   
     
     
         12 . The coating and surface repair method according to  claim 11 , wherein the forming results in a repaired surface with fatigue and mechanical strength properties comparable to that of the original carburized steel surface. 
     
     
         13 . The coating and surface repair method according to  claim 11 , wherein the damaged hardened steel surface has defects of sizes between 0.005-0.040 inches in diameter and depth. 
     
     
         14 . The coating and surface repair method according to  claim 11 , wherein the executing of the thermal spray process comprises maintaining combustion temperatures within a range of 1900-2300° C. 
     
     
         15 . The coating and surface repair method according to  claim 11 , wherein the ceramic metallic coating comprises at least one of a Tungsten-Carbide Cobalt (WC/Co) material and a Tungsten-Carbide Cobalt-Chromium (WC/Co—Cr) material.