Annealing effects in Al–Sc alloys

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2007-07, Vol.462 (1), p.370-374
• Main Authors: Smola, B., Stulíková, I., Očenášek, V., Pelcová, J., Neubert, V.
• Format: Article
• Language: English
• Subjects: Al alloys; Applied sciences; Cross-disciplinary physics: materials science; rheology; Elasticity. Plasticity; Electrical resistivity; Exact sciences and technology; Isochronal annealing; Magnesium; Materials science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Other heat and thermomechanical treatments; Physics; Scandium; Treatment of materials and its effects on microstructure and properties
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2005.11.075

Al–0.5Sc–0.4Zr and Al–2.7Mg–0.14Sc–0.045Zr alloys (numbers indicate wt.%) were prepared by powder metallurgy. Both materials contained a fine dispersion of spherical Al 3(Sc 1− x Zr x ) particles, which developed during extrusion at 350 °C. Cold and hot rolling of the as extruded Al–2.7Mg–0.14Sc–0.045Zr alloy influence the isochronal electrical resistivity annealing curves. The relative resistivity changes measured reflect recovery of the dislocation structure as well as precipitation and dissolution of β″, β′ and/or β phases of the Al–Mg system and the Al 3(Sc 1− x Zr x ) phase. Precipitation of very fine Guinier–Preston zones or particles of the β″ phase increase the resistivity of both as-extruded and cold rolled Al–2.7Mg–0.14Sc–0.045Zr alloy. Despite recovery of dislocations in the cold rolled Al–2.7Mg–0.14Sc–0.045Zr alloy between 150 and 180 °C, isochronal annealing curves of hardness HV10 show that very good mechanical properties persist up to 350 °C due to the stability of Al 3(Sc 1− x Zr x ) phase particles.