Rare earth-transition metal alloy articles
AssigneeROLLS-ROYCE plc
InventorJ. Shipton
Life of this patent
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Abstract
A phosphate bonded ceramic is used to provide a protective coating on a rare earth-transition metal (RE-TM) alloy substrate, conferring degradation resistance to the alloy by being oxidation resistant and acting as a diffusion barrier, thereby minimising/preventing oxygen diffusion and elemental depletion. The alloy substrate may, for example, be a permanent magnetic alloy component and may be used in aerospace applications.
Claims15
A rare earth-transition metal (RE-TM) alloy structure comprising a RE-TM alloy substrate and a diffusion barrier disposed thereon, wherein the diffusion barrier comprises a phosphate bonded ceramic wherein the rare earth is samarium.
A method of forming a diffusion barrier on a rare earth-transition metal (RE-TM) alloy substrate, the method comprising applying to the alloy substrate a coating comprising a source of a ceramic-forming metal oxide and a source of a phosphate binder for the metal oxide, and causing the metal oxide and the phosphate to cure to form a diffusion barrier comprising a phosphate bonded ceramic on the alloy substrate.
A method of reducing rare earth metal depletion at the surface of a RE-TM permanent magnet, which method comprises providing over the surface a diffusion barrier composed of a phosphate bonded ceramic.
Dependencies are inferred from the claim text.