Patent ID: 8084096

Claim:
A method for forming alumina whiskers on the surface of an aluminum-containing metallic alloy fiber comprising steps in the sequence of: a) selecting an aluminum-containing metallic alloy fiber having a diameter that ranges from approximately 12 microns to approximately 40 microns, wherein the metallic alloy composition is selected from the group consisting of MCrAlX, where M is at least one of iron (Fe), nickel (Ni) and cobalt (Co), Cr is chromium, Al is aluminum and X is at least one of yttrium (Y), zirconium (Zr), hafnium (Hf) and ytterbium (Yb); b) applying a layer of hafnium oxide to coat the metallic alloy fiber; and c) heating the hafnium oxide coated metallic alloy fiber at temperatures from approximately 800° C. to approximately 1000° C. for a period of time between approximately 50 hours to approximately 200 hours to form a plurality of alumina whiskers on the surface of the metallic alloy fiber and transform gamma or theta alumina to alpha alumina thereby preserving the structural integrity of the metallic alloy fiber having a plurality of alumina whiskers on the surface thereof.