ChemInform Abstract: A DIFFUSIONLESS PHASE TRANSFORMATION OF ALUMINUM‐MAGNESIUM (AL3MG2) INTERMETALLIC COMPOUND

Thermal stability of Al–Mg alloys after solidification under high pressures

“…The DSC curve under normal pressure only exhibits an endothermic peak ascribed to the diffusionless transformation, which is highlighted in Fig. 2b [20]. No endothermic peak of GP zones dissolution similar to those in Fig.…”

“…The DSC curve under normal pressure presents two different endothermic peaks, the one in the range 77-120°C is due to the dissolution of GP zones formed during natural ageing at room temperature; the other in the range 240-270°C is due to the diffusionless transformation that is shown in Fig. 1b [20]. The DSC curves of Al-32Mg alloy solidified under high pressures all present three thermal peaks, one is an endothermic peak due to the dissolution of GP zones and the other two are exothermic peaks.…”

“…(a) The whole curves, (b) high magnification of the endothermic peak under 2 GPa related to the dissolution of GP zones and (c) the endothermic DSC peak related to the diffusionless transformation of Al-42Mg alloy solidified under normal pressure[20].…”

Magnetic and transport properties of the giant-unit-cell Al3.26Mg2 complex metallic alloy

“…In another work on the AleMg system [20], a diffusionless phase transformation to a lower-symmetry phase (with its details undetermined) was reported to occur within the homogeneity range of the b-Al 3 Mg 2 phase. The transition temperature was found to be strongly concentration dependent, occurring at about 510 K for 38.2 at.% Mg and decreasing to 270 K for 39.7% Mg.…”

Contraction of aluminum alloys during and after solidification

“…On the other hand, the linear thermal expansion coefficients of the involved phases are quite different, being approximately 32 ϫ 10 Ϫ6 K Ϫ1 at 420°C [21] or 38 ϫ 10 Ϫ6 K Ϫ1 at 500°C [18] for alloys close to Al 8 Mg 5 and 17.4 ϫ 10 Ϫ6 K Ϫ1 in the range from 100°C to 500°C [22] for Al 2 Cu. Therefore, the application of a mixture rule gives the increase in the LTEC with concentration in heterogeneous Al-Mg alloys and the opposite trend in the case of Al-Cu alloys.…”