CoCr Alloy Carbide Composite Coatings for High-Temperature Applications

Abstract

A method for applying a coating, includes: providing a mixture of powders of comprising by volume percent: 10.0 to 60.0 one or more cobalt-based alloys and 5.0 to 70.0 WC—Ni; and spraying the mixture on a metallic substrate. Each of the cobalt-based alloys have by weight percent: Co as a largest constituent; 20.0-35.0 Cr; up to 3.0 C, if any; and up to 4.0 Ni, if any.

What is claimed is: 
     
         1 . A method for applying a coating, the method comprising:
 providing a mixture of powders comprising by volume percent:
 10.0 to 60.0 one or more cobalt-based alloys, each having by weight percent:
 Co as a largest constituent; 
 20.0-35.0 Cr; 
 up to 3.0 C, if any; and 
 up to 4.0 Ni, if any; and 
 
 5.0 to 70.0 WC—Ni; and 
   spraying the mixture on a metallic substrate.   
     
     
         2 . The method of  claim 1  wherein the mixture of powders comprises by volume percent:
 12.0 to 55.0 said one or more cobalt-based alloys; and 
 10.0 to 65.0 said WC—Ni. 
 
     
     
         3 . The method of  claim 1  wherein:
 the mixture of powders further has by volume percent 5.0 to 85.0 Cr 3 C 2 . 
 
     
     
         4 . The method of  claim 3  wherein the mixture of powders comprises by volume percent:
 10.0 to 30.0 said one or more cobalt-based alloys; 
 8.0 to 30.0 said WC—Ni; and 
 50.0 to 80.0 said Cr 3 C 2 . 
 
     
     
         5 . The method of  claim 1  wherein:
 the powder of WC—Ni is an agglomerated and sintered WC—Ni. 
 
     
     
         6 . The method of  claim 1  wherein:
 the spraying is HVOF spraying or HVAF spraying or cold spray. 
 
     
     
         7 . The method of  claim 1  wherein:
 the spraying is to a thickness of 75 micrometers to 130 micrometers. 
 
     
     
         8 . The method of  claim 1  the one or more cobalt-based alloys each comprise by weight percent:
 Co as said largest constituent; 
 25.00 to 32.00 Cr; 
 0.9 to 2.0 C; 
 3.0 to 6.0 W; 
 1.0-4.0 Fe; 
 up to 1.5 Mn, if any; 
 0.5 to 2.0 Si; 
 up to 0.1 P, if any; 
 up to 0.1 S, if any; 
 up to 2.0 Mo, if any; and 
 1.0-4.0 Ni. 
 
     
     
         9 . The method of  claim 1  the one or more cobalt-based alloys each comprise by weight percent:
 Co as said largest constituent; 
 28.00 to 32.00 Cr; 
 0.9 to 2.0 C; 
 3.0 to 6.0 W; 
 up to 3.0 Fe, if any; 
 0.5 to 2.0 Mn; 
 0.2 to 2.0 Si; 
 up to 0.04 P, if any; 
 up to 0.03 S, if any; 
 up to 1.50 Mo, if any; and 
 up to 3.0 Ni, if any. 
 
     
     
         10 . The method of  claim 1  wherein the mixture of powders comprises by volume percent:
 30.0 to 60.0 said one or more cobalt-based alloys; and 
 40.0 to 70.0 said WC—Ni. 
 
     
     
         11 . The method of  claim 10  wherein the mixture of powders comprises by volume percent:
 up to 20.0 Cr 3 C 2 , if any. 
 
     
     
         12 . The method of  claim 11  wherein the mixture of powders comprises by volume percent:
 up to 10.0 Cr 3 C 2 , if any. 
 
     
     
         13 . The method of  claim 1  the mixture of powders comprises by volume percent:
 10.0 to 30.0 said one or more cobalt-based alloys; 
 8.0 to 30.0 said WC—Ni; and 
 50.0 to 80.0 Cr 3 C 2 . 
 
     
     
         14 . The method of  claim 1  wherein:
 the substrate is a split ring seal substrate and the spraying is at least to an outer diameter surface of the substrate; or 
 the substrate is a spring compression seal substrate and the spraying is at least to an outer an axial end surface portion of the substrate; 
 the substrate is a HALO seal substrate and the spraying is to an inner diameter surface of the substrate; or 
 the substrate is a locating pin substrate and the spraying is to a base of the locating pin or a distal end section of the locating pin; or 
 the substrate interfaces with a locating pin and the spraying is to a counterface surface for the locating pin; or 
 the substrate is a snap fastener substrate and the spraying is to a shaft and a barb underside; or 
 the substrate is of a component having a snap fit bead or groove and the spraying is to said bead or groove; or 
 the substrate is of a component having a tab and the spraying is to a face of the tab; or 
 the substrate is of a component having a seal counterface and the spraying is to the seal counterface. 
 
     
     
         15 . The method of  claim 1  wherein:
 the substrate is a seal substrate and the spraying is at least to a contact surface portion of the substrate. 
 
     
     
         16 . An article comprising:
 a metallic substrate; and   a coating on the metallic substrate;   
       wherein the coating comprises by volume percent:
 18.0 to 50.0 an alloy having, by weight percent, Co as a largest constituent and 20.0-35.0 Cr; and 
 11.0 to 70.0 WC—Ni. 
 
     
     
         17 . The article of  claim 16  wherein the coating further comprises by volume percent:
 up to 65% Cr 3 C 2 , if any and wherein at last 95% by volume exclusive of porosity is said alloy, said WC—Ni, and said Cr 3 C 2 , if any. 
 
     
     
         18 . The article of  claim 16  wherein:
 the coating has a thickness of 50 micrometers to 200 micrometers. 
 
     
     
         19 . The article of  claim 16  wherein:
 the substrate forms a split ring; and 
 the coating is on an outer diameter surface of the substrate. 
 
     
     
         20 . The article of  claim 16  wherein:
 the substrate is a nickel-based superalloy or cobalt-based superalloy. 
 
     
     
         21 . The article of  claim 16  further comprising:
 a counterface in sliding engagement with the coating and comprising a nickel-based superalloy substrate. 
 
     
     
         22 . The article of  claim 16  wherein:
 the substrate is a split ring seal substrate and the spraying is at least to an outer diameter surface of the substrate; or 
 the substrate is a spring compression seal substrate and the spraying is at least to an outer an axial end surface portion of the substrate; 
 the substrate is a HALO seal substrate and the spraying is to an inner diameter surface of the substrate; or 
 the substrate is a locating pin substrate and the spraying is to a base of the locating pin or a distal end section of the locating pin; or 
 the substrate interfaces with a locating pin and the spraying is to a counterface surface for the locating pin; or 
 the substrate is a snap fastener substrate and the spraying is to a shaft and a barb underside; or 
 the substrate is of a component having a snap fit bead or groove and the spraying is to said bead or groove; or 
 the substrate is of a component having a tab and the spraying is to a face of the tab; or 
 the substrate is of a component having a seal counterface and the spraying is to the seal counterface.