Thermal spray applications using iron based alloy powder
A thermal spray powder is provided for use in a thermal spray technique, such as flame spraying, plasma spraying, cold spraying, and high velocity oxygen fuel spraying (HVOF). The thermal spray powder is formed by water or gas atomization and comprises 3.0 to 7.0 wt. % carbon, 10.0 to 25.0 wt. % chromium, 1.0 to 5.0 wt. % tungsten, 3.5 to 7.0 wt. % vanadium, 1.0 to 5.0 wt. % molybdenum, not greater than 0.5 wt. % oxygen, and at least 40.0 wt. % iron, based on the total weight of the thermal spray powder. The thermal spray powder can be applied to a metal body, such as a piston or piston ring, to form a coating. The thermal spray powder can also provide a spray-formed part.
1. A method of forming a powder metal material for use in a thermal spray technique, comprising the steps of:
providing a melted iron based alloy consisting of 3.8 wt. % carbon, 13.0 wt. % chromium, 2.5 wt. % tungsten, 6.0 wt. % vanadium, 1.5 wt. % molybdenum, 0.2 wt. % oxygen, 70.0 to 80.0 wt. % iron, and impurities in an amount not greater than 2.0 wt. %, based on the total weight of the melted iron based alloy; and
atomizing the melted iron based alloy to provide atomized droplets of the iron based alloy.
2. A method of forming a powder metal material for use in a thermal spray technique, comprising the steps of:
providing a melted iron based alloy including 3.0 to 7.0 wt. % carbon, 10.0 to 25.0 wt. % chromium, 1.0 to 5.0 wt. % tungsten, 3.5 to 7.0 wt. % vanadium, 1.0 to 5.0 wt. % molybdenum, not greater than 0.5 wt. % oxygen, and at least 40.0 wt. % iron, based on the total weight of the melted iron based alloy;
atomizing the melted iron based alloy to provide atomized droplets of the iron based alloy; and
grinding the atomized droplets.
3. The method of claim 1 , wherein the atomizing step includes forming metal carbides in the iron based alloy in an amount of at least 15.0 vol. %, based on the total volume of the iron based alloy.
4. The method of claim 3 , wherein the metal carbides are selected from the group consisting of: M 8 C 7 , M 7 C 3 , and M 6 C, wherein M is at least one metal atom and C is carbon.
5. The method of claim 4 , wherein M 8 C 7 is (V 63 Fe 37 ) 8 C 7 , M 7 C 3 is selected from the group consisting of: (Cr 34 Fe 66 ) 7 C 3 , Cr 3.5 Fe 3.5 C 3 , and Cr 4 Fe 3 C 3 ; and M 6 C is selected from the group consisting of: Mo 3 Fe 3 C, Mo 2 Fe 4 C, W 3 Fe 3 C, and W 2 Fe 4 C.
6. A wear resistant component, comprising: a thermal-sprayed powder metal material, wherein said thermal-sprayed powder metal material consists of 3.8 wt. % carbon, 13.0 wt. % chromium, 2.5 wt. % tungsten, 6.0 wt. % vanadium, 1.5 wt. % molybdenum, 0.2 wt. % oxygen, 70.0 to 80.0 wt. % iron, and impurities in an amount not greater than 2.0 wt. %, based on the total weight of said thermal-sprayed powder metal material.
7. The wear resistant component of claim 6 further comprising a body with an outer surface, and wherein said thermal-sprayed powder metal material is disposed on said outer surface.
8. The wear resistant component of claim 7 wherein said body is a piston ring presenting an inner surface surrounding a center axis and an outer surface facing opposite said inner surface, and said thermal-sprayed powder metal material forms a coating on said outer surface.
9. The wear resistant component of claim 7 wherein said body is a piston presenting an outer surface, and said thermal-sprayed powder metal material forms a coating on said outer surface.
10. The wear resistant coating of claim 6 wherein said wear resistant component consists of said thermal-sprayed powder metal material.
11. The wear resistant coating of claim 10 wherein said wear resistant component is a piston ring.
12. The wear resistant component of claim 6 including a second powder metal material mixed with said thermal-sprayed powder metal material.
13. A method of forming a wear resistant component, comprising the steps of:
spraying a powder metal material which has been atomized and ground into atomized droplets, wherein the powder metal material comprises 3.0 to 7.0 wt. % carbon, 10.0 to 25.0 wt. % chromium, 1.0 to 5.0 wt. % tungsten, 3.5 to 7.0 wt. % vanadium, 1.0 to 5.0 wt. % molybdenum, not greater than 0.5 wt. % oxygen, and at least 40.0 wt. % iron, based on the total weight of the powder metal composition.
14. The method of claim 13 wherein the spraying step is a thermal spray technique selected from the group consisting of: powder flame spraying, plasma spraying, cold spraying, and high velocity oxygen fuel spraying (HVOF).
15. The method of claim 13 including heating the powder metal material before the spraying step, and wherein the powder metal material is heated during the spraying step.
16. The method of claim 13 wherein the thermal spray technique includes providing a combustion chamber containing a mixture of fuel and oxygen; igniting the mixture of fuel and oxygen; and feeding the powder metal material into the combustion chamber after the igniting step to accelerate the powder metal material.
17. The method of claim 16 wherein the igniting step includes creating a pressure in the combustion chamber, and accelerating the powder metal material up to a supersonic velocity.
18. The method of claim 13 including providing a body, and wherein the spraying step includes spraying the powder metal material onto the body.
19. The method of claim 13 wherein the spraying step forms the wear resistant component, and the wear resistant component is a piston ring presenting an inner surface surrounding a center axis and an outer surface facing opposite the inner surface.