The Influence of Silicon Content on Recrystallization of Twin-Roll Cast Aluminum Alloys for Heat Exchangers

Abstract

Thin foils of aluminum alloys are commonly used in automotive industry for manufacturing heat exchangers. Use of twin-roll casting instead of direct-chill casting requires modications in the manufacturing process and use of improved materials. In the present study, the evolution in microstructure and mechanical properties during isochronal annealing of two AW3003-based alloys diering in silicon content was monitored. The silicon inuenced both the microhardness and precipitation kinetics during annealing, but not the recrystallization temperature. Precipitation of cubic α-Al15(Mn,Fe)3Si2 phase occurred in two steps in the material with higher Si content, while mainly precipitates of Al6(Mn,Fe) phase formed in the second material in a broad temperature interval, preferentially at grain boundaries.

The Evolution of Microstructure and Mechanical Properties of Al-Mn-Fe-Si Alloys During Isothermal Annealing

“…• C for 8 h. This treatment led to the formation of a ne dispersion of Al 3 Zr precipitates [16]. Both, the as-cast material and the annealed one were subjected to four ECAP passes at room temperature, employing the pressing speed 10 mm/min and the route B c , where the sample is rotated by 90…”

Grain Structure and Microhardness Development of Twin-Roll Cast Aluminum Strips after Constrained Groove Pressing

“…TEM of the as-cast sample shows the material containing a relatively low dislocation density (Fig. 5) with dislocations arranged in dislocation walls as commonly observed in TRC alloys [15]. CGP leads to a significant hardening.…”

Recrystallization in Multilayer Al99.99/AlMg3 Laminates Prepared by Accumulative Roll-Bonding

“…The following signicant increase of resistivity could not be explained by a simple dissolution of particles because TEM observations shows an opposite eect formation of Mn-rich particles, which is always connected with the decrease of resistivity [9,10]. Nevertheless, the diusion of solutes (Mg, Mn, Fe) into Al layers is highly probable.…”

“…• C. Such a behavior is typical for heavily deformed aluminum alloys and is always connected with the recovery of the dislocation substructure [8] and precipitation of Mn rich particles [9,10].…”