Electrospark deposition process for oxidation resistant coating of cooling hole

Abstract

A method of providing an oxidation resistant coating is disclosed. The method includes providing a substrate having a first surface and cooling holes. A portable coating device includes electro-spark deposition (ESD) equipment and an ESD torch connected with the ESD equipment. The ESD torch has an inert gas source and a rotary electrode conductive material. The rotary electrode is positioned within the ESD torch, and is shielded by an inert gas. The rotary electrode applies a compositionally controlled protective coating to the first surface of the substrate. Then the rotary electrode is inserted into the cooling hole and generates an electrospark between rotary ESD electrode and the substrate to form a rounded edge and deposit a coating of electrode material alloy at a cooling hole edge.

What is claimed is: 
     
         1 . A turbine engine component of a metal frame substrate including cooling holes, wherein at least one of the cooling holes comprises a rounded edge with a coating adjacent a first surface, wherein the rounded edge with the oxidation resistant coating is applied using a method for providing the coating, comprising:
 providing the substrate having the first surface and the at least one cooling hole;   providing a portable coating device including:
 electro-spark deposition (ESD) equipment, and 
 an ESD torch electrically connected with the ESD equipment, the ESD torch including: 
 an inert gas source; and 
 a rotary electrode including a conductive material, the rotary electrode disposed within the ESD torch, the rotary electrode shielded by an inert gas, wherein rotary electrode applies a compositionally controlled protective coating to the first surface of the substrate; 
   inserting the rotary electrode at least partially into the at least one cooling hole;   generating an electrospark between the rotary ESD electrode and the substrate to only form the rounded edge as a result of deformation of material from the substrate at an edge of the cooling hole and deposit a coating of electrode material alloy having a thickness of 3 mils or less over the rounded edge.