Microstructure of differently treated Al-Mg-Sc-Zr alloys

Abstract

The microstructures of different treated Al-5Mg-0.2Sc-0.1Zr alloys have been studied with optical microscopy and transmission electron microscope (TEM). Coherent particles with the matrix were found in as-cast sample, composite Al₃Sc/Al₃Zr particles were found after 13 h homogenized treatment under 470 °C. Coherent precipitates pinned dislocations and low-angle grain boundaries, and then restrained recrystallization. All kinds of particles of different treatments were not larger than 40 nm. After high-temperature stabilization treatments, most particles remain coherent with the matrix. The reasons of microstructure change at different treated conditions have been analyzed.

Keywords

Al-Mg-Sc-Zr alloy / microstructure / Al₃(Sc, Zr) / coherent and non-coherent

References

[1] BlakeN, HopkinsM A. Constitution and age hardening of Al-Sc alloys. J Mater Sci, 1985, 20: 2861-2867

[2] SawtellRalph, Jensen CraigL. Mechanical properties and microstructures of Al-Mg-Sc-alloys. Metallur Transactions A, 1990, 21A: 421-424

[3] Hyung-HoJo, Shin-ItirohFujikawa. Kinetics of precipitation in Al-Sc alloys and low temperature solid solubility of scandium in aluminium studied by electrical resistivity measurements. Mater Sci Eng, 1993, A171: 151-161

[4] KaygorodovaL I, DomashnikovV P. Investigation of the influence of scandium on the structure and properties of an aluminium-magnesium alloy during natural ageing. Phys Met Metall, 1989, 68(4): 160-166

[5] TormaT, Kovacs-csetenyiE, TurmezeyT, et al.. Hardening mechanisms in Al-Sc alloys. J Mater Sci, 1989, 24: 3925-3927

[6] ToropovaL S, KamardinkinA N, KindzhibaloV V, et al.. Investigation of alloys of the Al-Sc-Zr system in the aluminium-rich range. Phys Met Metall, 1990, 70(6): 106-110