Paper Title:
Crystal Analysis of Nonequilibrium δnon-Phase in Al-Li-Mg Alloys
  Abstract

The nonequilibrium δnon-phase was originally investigated in the work[1] when studying the ageing processes of the 1424 alloy ( Al-Li-Mg-system). As shown in the work[2] this phase may also be formed during the cooling from the temperature of SSHT. The δnon-phase precipitates are also present in 1420 alloy of the same system[3]. The basic structure investigations were carried out on the 1424 alloy sheets aged in accordance with the regime: 125°C, 32 hrs. The investigations were performed by TEM using the JEOL JEM 200CX microscope. The diffraction patterns from the δnon-phase on the crystallographic axes of zones close to <110>, <111>, <112> were obtained. It can be seen that the regular reflex networks appeared after the deviation from axes of zones by 3-4˚. It was established that the lattice parameters of δnon-phase and its orientation relation with the matrix can be approximately described by the following way: aδnon≈ aα/2[112] b δnon ≈a α/2[110] cδnon≈ a α [111] where aα- the period of the FCC- lattice of solid solution. The model of the crystallographic structure of the δnon-phase precipitates is proposed. On the basis of this model the mechanism of the δnon-phase formation is discussed. The late ageing stages are analyzed and it was shown that the δnon-phase particles are the nuclei for S1(Al2LiMg)- phase.

  Info
Periodical
Materials Science Forum (Volumes 519-521)
Edited by
W.J. Poole, M.A. Wells and D.J. Lloyd
Pages
259-264
DOI
10.4028/www.scientific.net/MSF.519-521.259
Citation
A.A. Alekseev, E.A. Lukina, D.V. Zaytsev, I.N. Fridlyander, "Crystal Analysis of Nonequilibrium δnon-Phase in Al-Li-Mg Alloys", Materials Science Forum, Vols. 519-521, pp. 259-264, 2006
Online since
July 2006
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Bao Hong Zhu, Bai Qing Xiong, Yon Gan Zhang, Udo Fritsching, Ji Shan Zhang, Feng Wang, Zhi Hui Li, Hong Wei Liu
Abstract:A high Zn content Al-Zn-Mg-Cu alloy was prepared by spray forming process and the precipitate behavior and microstructure of the extruded...
481
Authors: Xiao Ping Luo, Lan Ting Xia, Ming Gang Zhang
Abstract:The effect of Cd and Sb addition on the microstructural and mechanical properties of as-cast AZ31 alloys was investigated and compared. The...
197
Authors: N.I. Vlasova, V.S. Gaviko, A.G. Popov, N.N. Shchegoleva, L.A. Stashkova, Dmitriy Gunderov, Xavier Sauvage
Abstract:Equiatomic FePd alloy in the ordered state has been processed by means of high-pressure torsion deformation (HPTD) and then annealed. X-ray...
392
Authors: Katarzyna Bałdys, Grzegorz Dercz, Łukasz Madej
Abstract:The ferromagnetic shape memory alloys (FSMA) are relatively the brand new smart materials group. The most interesting issue connected with...
171
Authors: Hong Wei Liu, Yon Gan Zhang, Jian Bo Zhang, Bao Hong Zhu, Feng Wang, Zhi Hui Li, Xi Wu Li, Bai Qing Xiong
Chapter 1: Materials Properties
Abstract:Microstructural characterization of Al-Cu-Mg-Ag alloy ageing at low and elevated temperature were investigated by differential scanning...
1225