Turbine component having a low residual stress ferromagnetic damping coating

Abstract

A turbine component having a low residual stress ferromagnetic damping coating. The ferromagnetic damping coating may include a ferromagnetic damping material applied in powder form, which may be directed at a surface of the substrate at an application velocity so that it causes partial plastic deformation of the surface while adhering to the surface of the substrate to create a ferromagnetic damping coating. The ferromagnetic damping coating has a balanced coating residual stress, including a tensile quenching stress component and a compressive peening stress component. The resulting coated substrate exhibits a high damping capacity.

I claim: 
     
         1 . A turbine component, comprising:
 a) a metal based substrate ( 20 ) having a substrate thickness ( 22 ), a surface ( 24 ), and a bulk hardness; and   b) a ferromagnetic damping coating ( 10 ) layer affixed to at least a portion of the surface ( 24 ) of the metal based substrate ( 20 ), thereby providing a coated substrate ( 100 ) and defining a coating-substrate interface, and wherein:
 i) the ferromagnetic damping coating ( 10 ) has a balanced coating residual stress and the balanced coating residual stress includes at least a tensile quenching stress component and a compressive peening stress component such that the balanced coating residual stress is within a range of about ±50 MPa; 
 ii) wherein a portion of the surface ( 24 ) of the metal based substrate ( 20 ) is plastically deformed as the coated substrate ( 100 ) is created by directing a ferromagnetic damping powder at the metal based substrate ( 20 ) with an application velocity of at least 450 m/s. 
   
     
     
         2 . The turbine component of  claim 1 , wherein the ferromagnetic damping coating ( 10 ) has a coating thickness ( 12 ) of about 2% to about 20% of the substrate thickness ( 22 ). 
     
     
         3 . The turbine component of  claim 1 , wherein the ferromagnetic damping powder is directed at the metal based substrate ( 20 ) at an application temperature of at least 800° C. 
     
     
         4 . The turbine component of  claim 1 , wherein the ferromagnetic damping coating ( 10 ) is applied to the metal based substrate ( 20 ) in a partially molten powder form and the ferromagnetic damping coating ( 10 ) has a coating thickness ( 12 ) of about 2% to about 20% of the substrate thickness ( 22 ). 
     
     
         5 . The turbine component of  claim 1 , wherein the coated substrate ( 100 ) has a damping loss factor of at least 3.6×10 −3  at a strain amplitude of 0.0466×10 −4  to 7.77×10 −4 . 
     
     
         6 . The turbine component of  claim 5 , wherein the coated substrate ( 100 ) is not subjected to an annealing temperature of above 700° C. for an annealing period of longer than 30 minutes. 
     
     
         7 . The turbine component of  claim 1 , wherein the ferromagnetic damping coating ( 10 ) comprises a material selected from the group consisting of, by weight percent: (a) about 16 percent chromium (Cr), about 1 percent to about 6 percent aluminum (Al), and the balance substantially iron (Fe); and (b) about 16 percent chromium (Cr), about 1 percent to about 4 percent molybdenum (Mo), and the balance substantially iron (Fe). 
     
     
         8 . The turbine component of  claim 1 , wherein the ferromagnetic damping coating ( 10 ) comprises, by weight percent, about 22 percent to about 38 percent nickel (Ni), and the balance substantially cobalt (Co). 
     
     
         9 . The turbine component of  claim 1 , wherein a hardness of the metal based substrate ( 20 ) at the coating-substrate interface is within 25% of the bulk hardness. 
     
     
         10 . The turbine component of  claim 1 , wherein in the second bending mode the coated substrate ( 100 ) has a damping loss factor of at least 5.9×10 −3  at a strain amplitude of 0.227×10 −4 . 
     
     
         11 . The turbine component of  claim 1 , wherein in the third bending mode the coated substrate ( 100 ) has a damping loss factor of at least 5.7×10 −3  at a strain amplitude of 0.0568×10 −4 . 
     
     
         12 . The turbine component of  claim 1 , wherein the metal based substrate ( 20 ) comprises at least one of titanium, titanium-based alloy, steel alloy, nickel, nickel-based alloy, aluminum, and aluminum-based alloy. 
     
     
         13 . A turbine component, comprising:
 a) a metal based substrate ( 20 ) having a substrate thickness ( 22 ), a surface ( 24 ), and a bulk hardness; and   b) a ferromagnetic damping coating ( 10 ) layer affixed to at least a portion of the surface (24) of the metal based substrate ( 20 ), thereby providing a coated substrate ( 100 ) and defining a coating-substrate interface, and wherein:
 i) the ferromagnetic damping coating ( 10 ) comprises a material selected from the group consisting of, by weight percent: (a) about 16 percent chromium (Cr), about 1 percent to about 6 percent aluminum (Al), and the balance substantially iron (Fe); and (b) about 16 percent chromium (Cr), about 1 percent to about 4 percent molybdenum (Mo), and the balance substantially iron (Fe); 
 ii) the ferromagnetic damping coating ( 10 ) has a balanced coating residual stress and the balanced coating residual stress includes at least a tensile quenching stress component and a compressive peening stress component such that the balanced coating residual stress is within a range of about ±50 MPa without subjecting the coated substrate ( 100 ) to an annealing temperature of above 700° C. for an annealing period of longer than 30 minutes; and 
   iii) wherein a portion of the surface ( 24 ) of the metal based substrate ( 20 ) is plastically deformed as the coated substrate ( 100 ) is created by directing a ferromagnetic damping powder at the metal based substrate ( 20 ) with an application velocity of at least 450 m/s.   
     
     
         14 . The turbine component of  claim 13 , wherein the ferromagnetic damping coating ( 10 ) is applied to the metal based substrate ( 20 ) in a partially molten powder form and the ferromagnetic damping powder is directed at the metal based substrate ( 20 ) at an application temperature of at least 800° C. 
     
     
         15 . The turbine component of  claim 13 , wherein the coated substrate ( 100 ) has a damping loss factor of at least 3.6×10 −3  at a strain amplitude of 0.0466×10 −4  to 7.77×10 −4 . 
     
     
         16 . The turbine component of  claim 13 , wherein a hardness of the metal based substrate ( 20 ) at the coating-substrate interface is within 25% of the bulk hardness. 
     
     
         17 . A turbine component, comprising:
 a) a metal based substrate ( 20 ) having a substrate thickness ( 22 ), a surface ( 24 ), and a bulk hardness; and   b) a ferromagnetic damping coating ( 10 ) layer affixed to at least a portion of the surface ( 24 ) of the metal based substrate ( 20 ), thereby providing a coated substrate ( 100 ) and defining a coating-substrate interface, and wherein:
 i) the ferromagnetic damping coating ( 10 ) comprises, by weight percent, about 22 percent to about 38 percent nickel (Ni), and the balance substantially cobalt (Co); 
 ii) the ferromagnetic damping coating ( 10 ) has a balanced coating residual stress and the balanced coating residual stress includes at least a tensile quenching stress component and a compressive peening stress component such that the balanced coating residual stress is within a range of about ±50 MPa without subjecting the coated substrate ( 100 ) to an annealing temperature of above 700° C. for an annealing period of longer than 30 minutes; 
 iii) wherein a portion of the surface ( 24 ) of the metal based substrate ( 20 ) is plastically deformed as the coated substrate ( 100 ) is created by directing a ferromagnetic damping powder at the metal based substrate ( 20 ) with an application velocity of at least 450 m/s; and 
 iv) a hardness of the metal based substrate (20) at the coating-substrate interface is within 25% of the bulk hardness. 
   
     
     
         18 . The turbine component of  claim 17 , wherein the ferromagnetic damping coating ( 10 ) is applied to the metal based substrate ( 20 ) in a partially molten powder form and the ferromagnetic damping powder is directed at the metal based substrate ( 20 ) at an application temperature of at least 800° C. 
     
     
         19 . The turbine component of  claim 17 , wherein the coated substrate ( 100 ) has a damping loss factor of at least 3.6×10 −3  at a strain amplitude of 0.0466×10 −4  to 7.77×10 −4 . 
     
     
         20 . The turbine component of  claim 17 , wherein the hardness of the metal based substrate ( 20 ) at the coating-substrate interface is within 5% of the bulk hardness.