A method for applying a NiAl based bond coat and a diffusion aluminide coating to a metal substrate comprises, in part, coating a portion of the external surface of the superalloy substrate, by physical vapor deposition with a layer of a NiAl based metal alloy, wherein the deposited NiAl based metal alloy includes a controlled amount of about 6 to 25 weight percent aluminum, wherein the deposited aluminum level of the NiAl based metal alloy is controlled to be about 50-100% of its final level after aluminizing to form a coated external portion; and subsequently, simultaneously aluminizing the coated external portion and a different surface of the superalloy substrate.
