New Internal Friction Peak in Hydrogenated Palladium(Materials, Metallurgy & Weldability)
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Relation between internal friction peak and hydrogen behavior was investigated, as the palladiums containing various aluminum contents were hydrogen-charged at various current densities and then aged at room temperature. Deformation twins, cracks and the phase transformation from α phase to β phase occurred by hydrogenation, and they depended on the current density and aluminum impurity. The four internal friction peaks mainly appeared in hydrogenated palladium at 1Hz. The peak at 80K is related to hydrogen concentration in the α phase or the β phase corresponding Gorsky effect. The peak at 110K is related to cold work peak with hydrogen and dislocation. Another new two peaks were found. The new peaks at 150K and at 170K are considered to be related to the interaction with hydrogen and deformation twin in the α phase and the β phase respectively. The internal friction peaks were affected by the current density of cathodic charging and aluminum impurity in the palladium. The peak at 80K was predominant for the sample with 0.0283mass% aluminum, the peak at 110K was highest for the sample with 0.01mass% aluminum and the peak at 150K was predominant for the sample with trace aluminum. The hydrogenation with high current density accelerated the transformation from β phase to α phase during aging at room temperature owing to the high internal stress and dislocation density.
- Transactions of JWRI
Transactions of JWRI 22(2), 239-247, 1993-12