US 6,602,356 B1 · CVD aluminiding process for producing a modified platinum aluminide bond coat for improved high temperature performance

Abstract

A method of depositing by chemical vapor deposition a modified platinum aluminide diffusion coating onto a superalloy substrate comprising the steps of applying a layer of a platinum group metal to the superalloy substrate; passing an externally generated aluminum halide gas through an internal gas generator which is integral with a retort, the internal gas generator generating a modified halide gas; and co-depositing aluminum and modifier onto the superalloy substrate. In one form, the modified halide gas is hafnium chloride and the modifier is hafnium with the modified platinum aluminum bond coat comprising a single phase additive layer of platinum aluminide with at least about 0.5 percent hafnium by weight percent and about 1 to about 15 weight percent of hafnium in the boundary between a diffusion layer and the additive layer. The bond coat produced by this method is also claimed.

Claims16

Dependent claims

A method of depositing a modified platinum aluminide diffusion coating onto a superalloy substrate, comprising the steps of:

applying a layer of a Pt-group metal over at least one surface of the superalloy substrate;
placing the Pt-group metal-coated superalloy substrate into a CVD retort;
generating an Al-halide gas in an external gas generator;
generating a modified reactive metal-halide gas by passing a portion of the Al-halide gas generated in the external gas generator into an internal gas generator, a portion of which extends into the retort and that includes at least one reactive metal to produce a modified reactive metal-halide gas;
mixing the Al-halide gas and the modified reactive metal-halide gas together;
passing the mixture of Al-halide gas and the reactive metal-halide gas over the Pt-group-plated, superalloy substrate in the retort for a preselected period of time at a preselected temperature;
and
co-depositing Al and the reactive metal onto the Pt-group plated superalloy substrate to form a reactive metal-modified platinum group aluminide coating over the substrate.

5 more elements

Dependencies are inferred from the claim text.

CVD aluminiding process for producing a modified platinum aluminide bond coat for improved high temperature performance

Life of this patent

CVD aluminiding process for producing a modified platinum aluminide bond coat for improved high temperature performance

Life of this patent

Abstract

Claims16