An analysis of cooling rate influence on the sequence of intermetallic phases precipitation in some commercial aluminium alloys

Abstract

In the present work the evolution of the morphology (examined by means of SEM ) and changes in the chemical composition (examined by means of EDS microanalysis) of the intermetallic phases precipitates, containing Fe and Mn, in AA3004 type alloy, slowly cooled and frozen at 580, 510 and 430 °C, was analysed. The morphology of the intermetallic phase particles, depending on their chemical composition and precipitation temperature, was determined. It has been stated that intermetallic phases Al 6FeMn and a-Al(FeMn)Si, of different stoichiometry, precipitate at successive stages of solidification and cooling. The a-Al(FeMn)Si phase particles chinese script (Fe/Mn=2.3, [Fe+Mn]/Si=2.1-2.5) and branches (Fe/Mn=2.7-3.1, [Fe+Mn]/Si=2.3) were observed.

Effect of Sphere Properties on Microstructure and Mechanical Performance of Cast Composite Metal Foams

“…As seen in Figure 8, branch-like intermetallic phases in the matrix contain large amount of Si at the outer layer and more concentration of Mn in the inner layers of branches, creating two distinct shades in the SEM images. This result agrees with other studies in which Mn content controls the diffusion of Si in Al-Fe intermetallic phases [14].…”

“…As previously reported [3,4,7,8] aluminum-steel (Al-S) CMF contains hard and brittle intermetallic from the Al-Fe-Si ternary system dispersed through the matrix of the material. The formation of intermetallics in the Al-Fe-Si system is a well-studied phenomena [9][10][11][12][13][14][15] and is due to the reciprocal diffusion of Fe and other alloying elements, like Cr and Ni, from the sphere wall into the Al-Si matrix, at the same time of diffusion of Al and Si from the matrix towards the sphere wall. Intermetallic formation in Al-S CMF influences the mechanical properties of the material and for that reason it has been widely studied [1][2][3][4][5][6][7][8].…”

Influence of the heat treatment on the precipitation of the intermetallic phases in commercial AlMn1FeSi alloy

“…Therefore, many efforts are focused on the possibility of the control of the processes of their formation, among other things, to eliminate and to minimise their negative effect on the functional properties of the material [1][2][3][4]. Processes of formation of these phases can occur during alloy solidification from the liquid phase [4][5][6] and during the cooling or the heat treatment in the solid state [1][2][3][4]7,8].…”

Microstructure and Microhardness Evolutions of High Fe Containing Near-Eutectic Al-Si Rapidly Solidified Alloy

“…It was reported that the intermetallic phases and observed in Fe-containing AlSi alloys follow another solidification path under nonequilibrium solidification condition which leads to the formation of metastable forms of and with different compositions [31][32][33][34][35]. Rapid solidification is considered as a nonequilibrium process; therefore it is expected to obtain a metastable and phases.…”