Effect of Sc and Zr additions on the microstructure and age hardening of an AlMg3MnCr alloy Structure and age hardening of AlMgMnCrScZr
The effect of small additions of Sc and Zr on phase transformations, microstructure and hardening during the ageing of AA5754 alloy was studied. Electrical resistometry and hardness (HV10) measurements were used together with the microstructural study by transmission electron microscopy. A fine dispersion of spherical Al{sub 3}(Sc{sub x}Zr{sub 1-x}) particles precipitated after the conventional thermal and mechanical treatment (homogenization 450 deg. C/4 h, hot working at 420 deg. C and cold working). The decomposition sequence of Al-Mg-Si system was observed, namely, metastable {beta}''{yields}metastable {beta}'{yields} stable {beta} phase, after the solutionizing treatment 585 deg. C/15 h and following isochronal annealing. Simultaneously, a stable Al{sub 3}(Sc{sub x}Zr{sub 1-x}) spherical phase precipitated in cube-to-cube orientation. The pronounced age hardening at 240 deg. C is due to the metastable {beta}'' phase precipitation. A combination of Al{sub 3}(Sc{sub x}Zr{sub 1-x}) spherical particles and cuboids of stable {beta} phase lead to another age-hardening peak at 360 deg. C.
- OSTI ID:
- 20748713
- Journal Information:
- Materials Characterization, Journal Name: Materials Characterization Journal Issue: 1 Vol. 51; ISSN 1044-5803; ISSN MACHEX
- Country of Publication:
- United States
- Language:
- English
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