High-temperature internal friction in polycrystalline Zircaloy-4

The high-temperature internal friction spectrum of polycrystalline Zircaloy-4 is investigated in detail, for a wide range of frequencies. Two internal friction maxima are observed. The lower-temperature peak is interpreted in terms of a relaxation mechanism produced by the sliding of particle-free g...

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Autores principales: Povolo, F., Molinas, B.J.
Formato: JOUR
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00222461_v21_n10_p3539_Povolo
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Sumario:The high-temperature internal friction spectrum of polycrystalline Zircaloy-4 is investigated in detail, for a wide range of frequencies. Two internal friction maxima are observed. The lower-temperature peak is interpreted in terms of a relaxation mechanism produced by the sliding of particle-free grain boundaries. The higher-temperature peak is attributed to the sliding of boundaries blocked by small precipitates. Values for the activation enthalpy and the preexponential factor for diffusion along grain boundaries are given, and the viscosity coefficient associated with grain-boundary sliding is determined as a function of temperature. © 1986 Chapman and Hall Ltd.