Mechanical alloying and thermal stability of the Co-Al alloys.

• Autorzy: Tretjakov K.V. , Portnoi V.K. , Fadeeva V. I.
• Konferencja: International Conference on Fabrication and Properties of Metallic Nanomaterials, Warsaw, 17-19 June, 2004.
• Języki publikacji: EN

Abstrakty

EN

The cobalt rich Co-Al alloys prepared by mechanical alloying (MA) have been investigated using X-ray analysis and differential scanning calorymetry. At the initial stage of MA fcc Co high-temperature modification transforms to the hcp Co low-temperature one. The prolongation of milling leads to reverse transformation Co (hcp) -> Co fcc (al) solid solution formation. The structural transformation of Co under ball milling is closely related to the amount of stacking faults accumulated in both modifications of Co during milling. Al dissolves only in fcc Co and increases its stability. Even small amount of Al (3 at. %) stabilizes the stacking faults in hcp Co and accelerates structural transformation to fcc modification. The amount of fcc Co (Al) solid solution increases with the milling time and the milling energy. MA of Co - 15-25 at. % Al powder mixtures results in CoAl intermetallic and fcc Co(Al) solid solution formation at the intermediate stage of the synthesis. The intermatallic phase is fractured by long term milling. MA of Co - 50 at. % powders leads to single-phase CoAl intermtallic formation. The thermal tratment at 720 degrees C of the alloys sinthesized by MA leads to decomposition of the solid solution into the following phases Co fcc (Al), B2 CoAl and Co3Al metastable phase (type L12). This metastable phase decomposes at higher temperature.

Słowa kluczowe

EN

mechanical alloying; thermal stability; alloy

PL

stopowanie mechaniczne; stabilność termiczna; stop

• Wydawca: Komitet Nauki o Materiałach PAN
• Czasopismo: Archives of Materials Science
• Rocznik: 2004
• Tom: Vol. 25, nr 4
• Strony: 547--552

Twórcy

autor

Tretjakov K.V.

• M.V. Lomonosov Moscow University, Department of Chemistry, Russia

autor

Portnoi V.K.

• M.V. Lomonosov Moscow University, Department of Chemistry, Russia

autor

Fadeeva V. I.

• M.V. Lomonosov Moscow University, Department of Chemistry, Russia

• M.V. Lomonosov Moscow University, Department of Chemistry, Russia

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