Method for in-situ markers for thermal mechanical structural health monitoring

Abstract

A method of monitoring the residual stress in surface and near surface regions of a component includes identifying predetermined locations on the surface of a component that are expected to experience high stress during normal operating conditions of the component. Marker particles are introduced into the component during additive manufacture of the component at the predetermined locations. Then, the residual stress of the component is measured at a location corresponding with the marker material using x-ray techniques.

1 . A component of a base alloy, formed by additive manufacturing, that is subjected to stress during operation, the component comprising a marker of a marker material different than the base alloy inserted in surface and near surface regions of the component at a predetermined location to allow residual stress measurements to be made on the component at the marker. 
     
     
         2 . The component of  claim 1 , wherein the pre-determined location comprises a region expected to undergo stress during normal operating conditions of the component. 
     
     
         3 . The component of  claim 1  wherein the residual stress measurements are x-ray diffraction measurements. 
     
     
         4 . The component of  claim 2  wherein the x-ray diffraction measurements are used to determine residual strain in the marker material by measuring lattice interplanar spacing of the marker material. 
     
     
         5 . The component of  claim 3  wherein the x-ray diffraction measurements are performed with an x-ray diffractometer. 
     
     
         6 . The component of  claim 3  wherein the X-ray diffraction measurements use beam sizes of about 1 mm to 2 mm. 
     
     
         7 . The component of  claim 1  wherein additive manufacturing comprises direct metal deposition, direct laser melting or direct laser deposition. 
     
     
         8 . The component of  claim 1  wherein the marker material is insoluble in the base alloy, does not form a second phase with the base alloy and otherwise does not react with the base alloy. 
     
     
         9 . The component of  claim 1  wherein the base alloy comprises titanium alloy and the marker material comprises cerium.