| 摘要 |
A method for applying a NiAl based bond coat and a diffusion aluminide coating to a metal substrate is disclosed. The method comprises providing a superalloy substrate, the superalloy substrate having an external surface; and optionally cleaning the external surface of the superalloy substrate. The method further comprises 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 and additionally 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. Advantageously, a diffusion aluminide layer is formed on the different surface and the NiAl based metal alloy becomes a NiAl based bond coat, wherein the NiAl based bond coat comprises between about 12 to 25 weight percent aluminum, and the NiAl based bond coat has a uniform distribution of aluminum and other modifying elements selected from at least one of Cr, Zr and Hf throughout the NiAl based bond coat.
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