Coating material and method of applying same for producing wear and corrosion resistant coated articles
AssigneeUnion Carbide Corporation
InventorMerle H. Weatherly
Life of this patent
Estimating the term…
Abstract
Wear and corrosion resistant coatings are obtained using the plasma or d-gun techniques and applying a coating material consisting of carbides and nickel-containing base alloy having 6-18 wt.% boron.
Claims21
A powder composition for deposition by a method producing a coating having an as-deposited density greater than 75 percent theoretical on a metal substrate, such coating having high wear and corrosion resistance
- comprising two or more components
- (a) the first component consisting of 0-25 wt.% of at least one binder taken from the class consisting of cobalt, iron, nickel and alloys thereof and at least one metal carbide taken from the class consisting of tungsten, chromium, vanadium, hafnium, titanium, zirconium, niobium, molybdenum, tantalum carbides, and compounds thereof;
- (b) the second component consisting essentially of a single alloy or a mixture of alloys with a total composition of 6.0 to 18.0 wt.% boron;
- 0-6 wt.% silicon;
- 0-20 wt.% chromium;
- 0-5 wt.% iron;
- balance nickel;
- said first component comprising 40-75 wt.% of the entire composition.
A powder composition for deposition over a metal carbide coating having a density greater than 75 percent theoretical on a metallic substrate, such powder consisting essentially of a single alloy or a mixture of alloys with a total composition of 6.0 to 18.0 wt.% B;
- 0-6 wt.% Si;
- 0-20 wt.% Cr;
- 0-5 wt.% Fe;
- balance nickel.
A method for producing a coating on a metallic substrate, such coating having high wear and corrosion resistance
- comprising
- (a) depositing by a method capable of producing a coating having an as-deposited density greater than 75 percent theoretical, a composition comprising two or more components;
- the first component consisting of 0-25 wt.% of at least one binder taken from the class consisting of cobalt, iron, nickel and alloys thereof and at least one metal carbide taken from the class consisting of tungsten, chromium, vanadium, hafnium, titanium, zirconium, niobium, molybdenum, tantalum carbides, and compounds thereof;
- the second component consisting essentially of a single alloy or a mixture of alloys with a total composition of 6.0 to 18.0 wt.% boron;
- 0-6 wt.% silicon;
- 0-20 wt.% chromium;
- 0-5 wt.% iron;
- balance nickel;
- said first component comprising 40-75 wt.% of the entire composition;
- (b) heating such deposited coating at a temperature greater than 950.degree. C. and for a time sufficient to cause substantial melting of said second component and reaction of said second component with a substantial portion of said first component;
- (c) cooling the coating allowing the formation of borides, carbides and intermetallic phases resulting in a coating having a hardness greater than 1000 DPH.sub.300 and being virtually fully dense with no interconnected porosity.
A method according to claim 12 wherein step (a) is carried out by the plasma technique and the deposited coating has a density greater than 75 percent of theoretical.
A method for producing a coating on a metallic substrate, such coating having high wear and corrosion resistance
- comprising
- (a) depositing by a method capable of producing a coating having an as-deposited density greater than 75 percent theoretical, a composition consisting of 0-25 wt.% of at least one of a binder taken from the class consisting of cobalt, iron, nickel and alloys thereof and at least one metal carbide taken from the class consisting of tungsten, chromium, vanadium, hafnium, titanium, zirconium, niobium, molybdenum, tantalum carbides, and compounds thereof;
- (b) depositing over said coating deposited by step (a) a composition consisting essentially of a single alloy or a mixture of alloys with a total composition of 6.0 to 18.0 wt.% boron;
- 0-6 wt.% silicon;
- 0-20 wt.% chromium;
- 0-5 wt.% iron;
- balance nickel;
- (c) heating the so-deposited coating of steps (a) and (b) at a temperature greater than 950.degree. C. and for a time sufficient to cause the coating of step (b) to penetrate and react with the coating of step (a);
- and
- (d) cooling the coating allowing the formation of borides, carbides and intermetallic phases resulting in a coating having a hardness greater than 1000 DPH.sub.300 and being virtually fully dense with no interconnected porosity.
A coating on a metallic substrate, said coating consisting of an interdiffusion zone with said substrate, and intermediate zone consisting of a gradient of borides, carbides and intermetallics in a metal matrix and a hard outer zone which may consist of one or more layers, said outer zone containing large, angular borides, carbides and intermetallic particles, and having a hardness of 1000 to 2200 DPH.sub.300.
Dependencies are inferred from the claim text.