The activity of non-basal slip systems and dynamic recovery at room temperature in fine-grained AZ31B magnesium alloys

• Published in: Acta materialia Vol. 51; no. 7; pp. 2055 - 2065
• Main Authors: Koike, J, Kobayashi, T, Mukai, T, Watanabe, H, Suzuki, M, Maruyama, K, Higashi, K
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 18.04.2003; Elsevier Science
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Deformation, plasticity, and creep; Dislocations; Exact sciences and technology; Magnesium; Materials science; Mechanical properties; Metals. Metallurgy; Microstructure; Physics; Treatment of materials and its effects on microstructure and properties; Mechanical properties; Magnesium; Microstructure; Dislocations; XRD; Plastic deformation; Experimental study; Stress-strain relations; Zinc alloys; Magnesium base alloys; Transmission electron microscopy; Aluminium alloys; Slip system; Fine grain structure
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/S1359-6454(03)00005-3

Fine-grained alloys of Mg-3Al-1Zn-0.2Mn in wt.% (AZ31B) were obtained by an equal-channel angular extrusion technique and subsequent annealing at elevated temperatures. Tensile tests were performed at room temperature at a strain rate of 1x10 -3 s -1. The alloys exhibited an apparent steady-state deformation region and a large tensile elongation of 47%. The deformed microstructure at an elongation of 2% indicated substantial cross-slip to non-basal planes induced by plastic compatibility stress associated with grain boundaries. The non-basal segment of dislocations was found to consist of 40% of the total dislocation density at a yield anisotropy factor of only 1.1 instead of an expected value of 100 obtained from single-crystal experiments. The deformed microstructure at an elongation of 16% indicated recovered regions within twins as well as untwinned matrices. These results indicate that dynamic recovery can occur in Mg alloys at room temperature.