Phase separation of a supersaturated nanocrystalline Cu Co alloy and its influence on thermal stability

Abstract

The thermal decomposition behavior, the microstructural evolution and its influence on the mechanical properties of a supersaturated Cu Co solid solution with ~100 nm average grain size prepared by severe plastic deformation is investigated under non-isothermal and isothermal annealing conditions. Pure fine grained Cu and Co exhibit substantial grain growth upon annealing, whereas the Cu Co alloy is thermally stable at the same annealing temperatures. The annealed microstructures are studied by independent characterization methods, including scanning electron microscopy, electron energy loss spectroscopy and atom probe tomography. The phase separation process in the Cu Co alloy proceeds by the same mechanism, but on different length scales: a fine scaled spinodal type decomposition is observed in the grain interior, simultaneously Co and Cu regions with a larger scale are formed near the grain boundary regions. Subsequent grain growth at higher annealing temperatures results in a microstructure consisting of the pure equilibrium phases. Such mechanisms can be used to tailor nano structures to optimize certain properties.

References in corpus (5)

• Grain boundaries in ultrafine grained materials processed by severe plastic deformation and related phenomena
• Nanostructure and properties of a Cu-Cr composite processed by severe plastic deformation
• Nanostructure and related mechanical properties of an Al-Mg-Si alloy processed by severe plastic deformation
• New insights on the formation of supersaturated solid solutions in the Cu Cr system deformed by high pressure torsion
• Homogeneous Cu-Fe super saturated solid solutions prepared by severe plastic deformation

Cited by in corpus (8)

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• Magnetic Binary Supersaturated Solid Solutions Processed by Severe Plastic Deformation
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• Excellent glass former Ni${}_{62}$Nb${}_{38}$ crystallizing under combined shear and ultra-high pressure
• On the magnetic nanostructure of a Co-Cu alloy processed by high-pressure torsion
• Oxide-stabilized microstructure of severe plastically deformed CuCo alloys
• Unusual effect of high pressures on phase transformations in Ni${}_{62}$Nb${}_{38}$ alloy