Effect of pre-deformation on aging characteristics and mechanical properties of a Mg–Gd–Nd–Zr alloy

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 491; no. 1; pp. 103 - 109
• Main Authors: Zheng, K.Y., Dong, J., Zeng, X.Q., Ding, W.J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-09-2008; Elsevier
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Elasticity. Plasticity; Exact sciences and technology; Materials science; Mechanical properties; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Mg–Gd–Nd–Zr alloy; Microstructure; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Pre-deformation; Precipitation; Solid solution, precipitation, and dispersion hardening; aging; Treatment of materials and its effects on microstructure and properties; Mechanical properties; Precipitation; Pre-deformation; Microstructure; Mg–Gd–Nd–Zr alloy; Strengthening; Twin boundary; Ductility; Ageing; Precipitate; Substructure; Rare earth metal alloy; Zirconium addition; Tension test; Dislocation; Dislocation density; Magnesium base alloys; Plasticity; Mg-Gd-Nd-Zr alloy; Strength; Gadolinium alloy; Neodymium alloy
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2008.01.067

The effect of plastic deformation prior to artificial aging on the aging characteristics and mechanical properties of a Mg–11Gd–2Nd–0.5Zr (wt.%) alloy was investigated. Induced pre-deformation ranged from 0% to 10% stretch, with an intermediate of 5% stretch. The as-stretched specimens processed high density of dislocations and twins, which increased with elevated deformation level. As compared to non-stretched alloy, the stretched alloy showed accelerated aging kinetics when aged at 200
°C. Comparison of microstructure in non-stretched and stretched specimens after 200
°C/24
h aging showed that pre-deformation contained not only homogeneous precipitates in the matrix but also heterogeneous precipitates at dislocations and twin boundaries. Tensile test results showed that pre-deformation enhanced the strength of the alloy but declined the ductility at temperature below 250
°C. The gain in strength for stretched and aged alloy was attributed to the strengthening of dislocation substructures and twin boundaries together with heterogeneous precipitates.