Grain‐boundary relaxation peak correlated to the precipitation in Cu–20.4Al–8.7Mn shape‐memory alloy. Issue 4 (30th January 2013)

• Record Type: Journal Article
• Authors: Hao, Gangling; Xu, Qiaoping; Wang, Hui; Wang, Weiguo
• Is Part Of: Physica status solidi. Volume 210:Issue 4(2013:Apr.)
• Page Start: 814
• Page End: 818
• Publication Date: 2013-01-30
• Subjects: Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201228766
• Languages: English
• ISSNs: 1862-6300

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The grain‐boundary relaxation as well as corresponding internal friction (IF) mechanism in Cu‐based shape‐memory alloy was investigated taking Cu–20.4Al–8.7Mn (at%) as an example. A relaxational IF peak was found at around 214 °C during the heating process, whereas the peak completely disappears during the subsequence cooling process. The IF peak with the activation energy and pre‐exponential factor of 1.60 eV and 3.8 × 10⁻¹⁸, respectively, shifting towards higher temperature as the measuring frequency increased indicates that the peak correlates to a thermal‐activation process. The results obtained revealed that the viscous sliding of the grain boundaries should be the operative mechanism for the appearance of the peak. However, the appearance of the γ₂ precipitate particles formed during the heating process provides a reverse contribution to the peak, leading to the disappearance of the peak due to their pinning effect on the grain boundaries.</p> </abstract>