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金属学报(英文版)
Ultrafine-grained pure aluminum L2 with a mean grain size of 1.0μm was produced by equal channel angular pressing (ECAP) and annealing at 150℃ for 2h. Damping behavior of the alloy was measured using a dynamic mechanical thermal analyzer. The alloy had an excellent damping capacity Q-1 with the ambient value being 9.8×l0-3 at 1.0Hz when the strain amplitude was 2.0×l0-5. The damping behavior of the alloy showed a non-linear damping variation tendency, that is, with an increase in temperature and a decrease of frequency, the damping capacity of the alloy increased. The damping capacity increased with the strain amplitude when the strain amplitude was less than 4.6×l0-5. When the strain amplitude was higher than 4.6×10-5, the damping capacity became a constant and independent of strain amplitude. The high damping capacity was attributed to dislocation unpinning and a drag of dislocation on pinning points.
关键词:
ECAP
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超细晶
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阻尼
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铝合金
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金属学报(英文版)
Nanocrystal ODS (oxide dispersion strengthening) aluminide coatings were produced on a stainless steel and nickel-based superalloy by the pack aluminizing process assisted by ball peening. Pure Al powders and 1% of ultra-fine Y2O3 powders were mixed by ball milling. The ultra-fine Y2O3 powders were dispersed in Al particles. Ball peening welded the Al particles onto the substrate and accelerated the formation of aluminide coating. Nanocrystal ODS aluminide coatings were produced by the outward growth at a much low temperature (below 600℃) in a short treatment time. The effects of the operation temperature and treatment time on the formation of the coatings were analyzed. SEM (scanning electron microscope), AFM (atomic force microscope), EDS (energy dispersive X-ray spectroscopy), XRF (X-ray fluorescence spectrometer) and XRD (X-ray diffraction) methods were applied to investigate the microstructure of the coatings. High-temperature oxidation tests were carried out to evaluate the oxidation resistance of the ODS aluminide coatings.
关键词:
nano-coating
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微米/纳米晶涂层
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球击处理过
