| 摘要 |
Methods for the manufacture of nanostructured metals, metal carbides, and metal alloys are presented, such metals including nanostructured aluminum, chromium, iron, molybdenum, vanadium, and steel. Preferably, the nanostructured steel is of the M50 type, and comprises iron, molybdenum, chromium, vanadium and carbon. Synthesis of M50 steel further comprising nanostructured aluminum, aluminum oxide, or aluminum nitride is also described. In accordance with an important feature of this invention, the grain size of the metals and metal alloys is in the nanometer range. In accordance with the method of the present invention, the nanostructured metals, metal carbides, and metal alloys are prepared via chemical synthesis from aluminum, iron, molybdenum, chromium and vanadium starting materials. Decomposition of metal precursors or co-precipitation or precipitation of metal precursors is followed by consolidation of the resulting nanostructured powders. Alternatively, nanostructured M50 steel may be obtained by mixing of nanocrystalline chromium, iron, molybdenum, and vanadium powders, followed by ball-milling, and consolidation. The nanostructured metals, metal carbides, and metal alloys of this invention find particular utility in the manufacture of cutting tools and bearings, and in ferrofluids, magnetic memory systems, and catalysis.
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