Elastic and anelastic properties of metals near their melting points from miscibility gap alloy composites

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• 作者：Anthony J. Rawson^a ; ^{anthony.rawson@newcastle.edu.au} ; Dylan T. Cuskelly^a ; Sarah L. Driver^b ; Michael A. Carpenter^b
• 关键词：Premelting ; Resonant ultrasound spectroscopy ; Miscibility gap alloy
• 刊名：Materials Science and Engineering: A
• 出版年：2017
• 出版时间：10 January 2017
• 年：2017
• 卷：681
• 期：Complete
• 页码：18-24
• 全文大小：1114 K
• 卷排序：681

文摘

A new method, using Miscibility Gap Alloy composites and Resonant Ultrasound Spectroscopy, has been developed to determine the temperature dependence of elastic and anelastic properties of metals up to and through their melting points. The experimental conditions of high frequency (f~106 Hz) and low strain (<10−6) significantly extend the frequency range available for determining, in particular, the high temperature background of acoustic loss seen at temperatures greater than half the melting point. For Sn at T<450 K and Bi, the frequency dependence of the loss appears to follow fn with n~0.2, assuming activation energies determined by lattice diffusion or pipe diffusion within dislocations. For Sn there appears to be a temperature interval up to the melting point with n≈1, which could be indicative of premelting. The same approach of using a soft metal matrix to support a second phase has also been demonstrated for measuring acoustic loss in powder samples of LaAlO3. It provides, in principle, a new method for determining elastic and anelastic properties of powder samples with grain sizes down to nanoscale.