Preparation of nanocrystalline alloys by mechanical alloying carried out at elevated temperatures

In a process for preparing a nanocrystalline powder of an alloy made of at least two metals, said nanocrystalline powder consisting of crystallites having a grain size lower than 100 nm, said process comprising the step of subjecting to an intensive mechanical grinding a powder of one of said at least two metals with a powder of every other one of said at least two metals in such amounts as to obtain said alloy, said intensive mechanical grinding being carried out at atmospheric pressure under an inert atmosphere and for a period of time sufficient to achieve formation of said crystallites and reduction of the grain size of said crystallites to lower than 100 nm;

• the improvement comprising carrying out said intensive mechanical grinding at an elevated temperature ranging from about 100.degree. C. to about 400.degree. C., whereby said crystallites of said grain size are obtained in a period of time lower by about an order of magnitude than that necessary to obtain said crystallites of said grain size by a substantially identical mechanical grinding step carried out at ambient temperature.