Microstructures and mechanical properties of HPT processed 6063 Al alloy

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 558; pp. 525 - 532
• Main Authors: Das, Mousumi, Das, Goutam, Ghosh, Mainak, Wegner, Matthias, Rajnikant, V., GhoshChowdhury, S., Pal, T.K.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.12.2012; Elsevier
• Subjects: 6063Al alloy; Aluminum base alloys; Applied sciences; Ball indentation technique; Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Defects and impurities in crystals; microstructure; Disks; Dislocations; Equivalence; Exact sciences and technology; Fine precipitation; Grains; Hardness; High-pressure torsion (HPT); Linear defects: dislocations, disclinations; Materials science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Microstructure; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Precipitation; Severe plastic deformation (SPD); Strain; Structure of solids and liquids; crystallography; Transmission electron microscopy (TEM); Treatment of materials and its effects on microstructure and properties; 6063Al alloy; High-pressure torsion (HPT); Fine precipitation; Severe plastic deformation (SPD); Ball indentation technique; Transmission electron microscopy (TEM); Vickers hardness; High strain; Ultimate strength method; Plastic deformation; Subgrain; Dislocation; Precipitation; Stress effects; Grain refinement; Grain size; Dislocation motion; Aluminium base alloys; Mechanical properties; Indentation; Microhardness; Steady state; Tensile strength; Transmission electron microscopy; High pressure torsion; Recrystallization; 6063AI alloy; Property structure relationship
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2012.08.040

6063 Al alloy is subjected to severe plastic deformation through high-pressure torsion (HPT) using disk samples. The values of the Vickers microhardness and equivalent strain were recorded along diameters in each disk. The microhardness of 6063 Al alloys increases strongly and continuously with increasing equivalent strain but levels off and enters into a steady-state where the hardness remains unchanged with further straining. It is confirmed that the yield and ultimate tensile strength also follows the same single role of the equivalent strain as the hardness. Transmission electron microscopy showed that a subgrain structure develops at an initial stage of straining with individual grains containing dislocations. When increasing the straining, the subgrain size decreases whereas the misorientation angle increases and more dislocations are formed within the grains. In the steady-state range, some recrystallized grains formed which are free from dislocations. The mechanism for the grain refinement is discussed in terms of dislocation mobility.