Influence of strain rate on the characteristics of a magnesium alloy processed by high-pressure torsion

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 528; no. 10; pp. 3601 - 3608
• Main Authors: Serre, Pauline, Figueiredo, Roberto B., Gao, Nong, Langdon, Terence G.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 25.04.2011; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deformation, plasticity, and creep; Disks; Exact sciences and technology; Grain size; Hardness; High-pressure torsion; Homogeneity; Homogeneous structure; Magnesium; Magnesium alloy; Magnesium base alloys; Materials science; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Physics; Strain rate; Torsion; Treatment of materials and its effects on microstructure and properties; Tribology and hardness; Ultrafine grains; Homogeneity; Ultrafine grains; Hardness; High-pressure torsion; Magnesium alloy; Grain size; Vickers hardness; Microhardness; Magnesium base alloys; High pressure torsion; Fine grain structure; Grain refinement; Strain rate
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2011.01.066

► The demonstration that it is possible to achieve a homogeneous structure in the AZ31 alloy after HPT. ► The influence of rotation rate in HPT processing. ► The effect of the local strain rate within the HPT disk. A commercial magnesium AZ31 alloy was processed by high-pressure torsion (HPT) through 5 turns at 453 K using three different rotation rates. The results show that HPT introduces significant grain refinement to an average grain size of ∼0.5 μm. The processed structures were heterogeneous in the centers of the disks and homogeneous at distances at and above ∼1 mm from the disk centers. The measured values of the microhardness were also reasonably homogeneous after HPT except only near the disk centers. The hardness values and the average grain sizes were correlated with the local strain rates by using the imposed rotation rates and estimates of the strains within the disks. The results demonstrate the hardness and the average grain size both exhibit a small dependence on the local strain rate.