Structural phase transition in Al-Cu-Mg-Si and Al-Mg-Si alloys: Ordering mechanisms and crystallographic structures
The precipitation state of the Al-Cu-Mg-Si and Al-Mg-Si alloys was investigated by TEM, EDS and HREM. In the Al-Cu-Mg-Si alloys, it has been shown that a structural phase transition exists between 3 phases: Q-Al5Cu2Mg8Si6, QC and QP. These phases, which have close compositions, are based on the same lattice, the QP lattice. A model of this transition has been developed by considering the ordering on the QP latent lattice of triangular clusters (found from the Q structure determined by X-ray). The model has been applied to the β′ and B′ phases in the Al-Mg-Si alloys. It has permitted to determine the structures of QC and β′, precise the mechanisms of ordering and perform Monte Carlo simulations on a honeycomb lattice. © 2000 Trans Tech Publications.
Keywords: Al-Cu-Mg-Si alloy ; Al-Mg-Si ; Aluminum alloys ; Computer simulation ; Crystal lattices ; Crystallography ; Crystal structure ; High resolution electron microscopy ; Honeycomb lattice ; HREM ; Metallographic phases ; Monte carlo ; Monte Carlo methods ; Order-disorder ; Order disorder transitions ; Phase composition ; Phase transitions ; Precipitation ; Precipitation (chemical) ; Q structure ; Structural phase transitions ; TEM ; Transmission electron microscopy
Record created on 2014-11-14, modified on 2016-08-09