Modified aluminum-containing protective coating and its preparation

摘要

A nickel-base superalloy substrate has an overlying protective coating including a modified aluminum-containing protective layer. The modified aluminum-containing protective layer is formed of nickel, aluminum, calcium in an amount of from about 50 to about 300 parts per million by weight, and, optionally, elements interdiffused into the modified aluminum-containing protective layer from the substrate. Magnesium or barium may be used instead of or in addition to the calcium. A ceramic layer may overlie the modified aluminum-containing protective layer.