摘要 |
Multiple layers of nickel phosphorous coatings are formed by electroless plating onto a base metal substrate such as a turbine component. In one embodiment, a first nickel layer metallurgical bonded by a heat treatment process to a surface of the base metal substrate, the first nickel layer containing about 4 to about 6 weight percent phosphorous with the balance being essentially nickel; and a second nickel layer deposited onto the first layer, the second nickel layer containing about 8 to about 12 weight percent phosphorous with the balance being essentially nickel, wherein the first and second layers are formed by electroless plating. In this manner, adhesion is maximized without degrading the properties of the second layer such as corrosion resistance and ductility. Also disclosed are processes for forming the multilayered nickel phosphorus coatings.
|