Journal of Materials Research

Table of Contents - 28 July 2012 - Volume  27   

Articles

Spontaneous formation of filamentary Cd whiskers and degradation of CdMgYb icosahedral quasicrystal under ambient conditions

Lu Lua1, Jianbo Wanga1 c1, He Zhenga1, Dongshan Zhaoa1, Renhui Wanga1 and Jianian Guia1

a1 School of Physics and Technology, Center for Electron Microscopy and MOE Key Laboratory of Artificial Micro- and Nano-structures, Wuhan University, Wuhan 430072, China

Abstract

The whiskers spontaneously grown in Cd–Mg–Yb alloy containing icosahedral quasicrystal as dominant phase have been investigated by electron microscopy. It is found that: (i) the whiskers are mainly composed of Cd with growth direction along ${{ \lt \bar 2110 \!\!> }}_{{\rm{Cd}}} $. CdO particles are frequently observed on surfaces of whiskers and the alloy, indicating the importance of the oxidation process during the whisker growth; (ii) there exist four types of orientation relationship between Cd and CdO. The interfaces between them are shown to accommodate large lattice misfit, which is well explained by near coincidence site lattice model; (iii) nanosized Cd particles are observed to aggregate around the whisker root, providing a convincing experimental evidence for the long-range atomic diffusion. Our study offers a unique opportunity to unveil the relationship between unstability of quasicrystal structure and whisker formation and may have some implications for oxidation process of metals.

(Received January 26 2012)

(Accepted April 18 2012)

Key Words:

  • Quasicrystal;
  • Transmission electron microscopy (TEM);
  • Whiskers

Correspondence:

c1 Address all correspondence to this author. e-mail: wang@whu.edu.cn

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