Thermal barrier coatings and methods of producing same

Abstract

A thermal insulating ceramic layer for use on metal alloy components exposed to hostile thermal and chemical environment, such as a gas turbine. The thermal barrier coating may include cracks made by a series of steps, including subjecting at least a portion of the thermal barrier coating to a shockwave such that microcracks are formed in the thermal barrier coating without also substantially deforming the substrate.

1 . A method for forming cracks in a thermal barrier coating applied to a gas turbine component, the method comprising the steps of:
 depositing a bond coating on a metallic substrate, wherein the bond coating comprises MCrAlY, where M is iron, cobalt, and/or nickel, and wherein the metallic substrate comprises a gas turbine component;   depositing a thermal barrier coating on the bond coating, wherein the thermal barrier coating comprises yttria-stabilized zirconia; and   subjecting at least a portion of the thermal barrier coating to a shockwave such that microcracks are formed in the thermal barrier coating and such that the metallic substrate is not substantially deformed.   
     
     
         2 . The method of  claim 1 , wherein the gas turbine component comprises a blade. 
     
     
         3 . The method of  claim 1 , wherein the thermal barrier coating comprises 8% yttria-stabilized zirconia. 
     
     
         4 . The method of  claim 1 , wherein the step of subjecting at least a portion of the thermal barrier coating to a shockwave comprises laser ablation or laser shock peening. 
     
     
         5 . The method of  claim 1 , wherein the step of subjecting at least a portion of the thermal barrier coating to a shockwave does not include subjecting the entire thermal barrier coating to the shockwave. 
     
     
         6 . The method of  claim 1 , wherein the step of depositing a bond coating on a metallic substrate comprises air plasma spraying the bond coating on the metallic substrate. 
     
     
         7 . A method of forming cracks in a ceramic-based coating comprising the steps of:
 depositing a ceramic-based coating on a metallic-based substrate, wherein the ceramic-based coating comprises a thermal barrier coating; and   subjecting at least a portion of the ceramic-based coating to a shockwave such that microcracks are formed in the ceramic-based coating and such that the metallic-based substrate is not substantially deformed.   
     
     
         8 . The method of  claim 7 , wherein the ceramic-based coating comprises yttria-stabilized zirconia. 
     
     
         9 . The method of  claim 7 , wherein the metallic-based substrate comprises a superalloy comprising at least one of iron, nickel, or cobalt.