Structure and tribological property of B2-based approximants |
| |
Authors: | Chuang Dong Li-Ming Zhang Qing-Gang Zhou Hui-Chen Zhang Jean-Marie Dubois Qiu-Hua Zhang Yao-Chun Fu Fei-Zhou He Fei Ge |
| |
Affiliation: | (1) State Key Lab. for Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, 116 024 Dalian, China;(2) Department of Materials Engineering, Dalian University of Technology, 116 024 Dalian, China;(3) Institute of Materials and Technology, Dalian Maritime University, 116 024 Dalian, China;(4) LSG2M, Centre D’Ingénierie des Matériaux, Parc de Saurupt, 54042 Nancy, France |
| |
Abstract: | The present paper is concerned with a special group of approximants with B2 superstructures. In the first part, recent work
on structural features of the B2 superstructure approximants is summarized. Experimental results obtained in Al-Cu-Mn and
Al-Cu systems are presented, where a series of B2-based approximants are observed. These phases all have similar valence electron
concentrations, in full support of thee/a-constant definition of approximants. Special emphasis is laid on the chemical twinning modes of the B2 basic structure in
relation to the Al-Cu approximants. It is revealed that the B2 twinning mode responsible for the formation of local pentagonal
atomic arrangements is of 180°/111] type. This is also the origin of 5-fold twinning of the B2 phase on quasicrystal surfaces.
Crystallographic features of phases B2, τ2, τ3,γ, and other newly discovered phases are also discussed. In all these phases, local pentagonal configurations are revealed.
In the second part, dry tribological properties of some AlCuFe samples containing the B2-type phases are presented. The results
indicated that the B2 phase having their valence ratio near that of the quasicrystal possesses low friction coefficient under
various loads, comparable with the annealed quasicrystalline ingot. Such a result indicates that the B2-type phase withe/a near that of quasicrystal is indeed an approximant, which is in full support of the valence electron criterion for approximants. |
| |
Keywords: | Quasicrystals approximants B2 crystal structures tribology |
本文献已被 SpringerLink 等数据库收录! |
|