Twist-channel angular pressing: effect of the strain path on grain refinement and mechanical properties of copper

• Published in: Journal of materials science Vol. 46; no. 24; pp. 7865 - 7876
• Main Authors: Kocich, Radim, Fiala, Jaroslav, Szurman, Ivo, Macháčková, Adéla, Mihola, Milan
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2011; Springer; Springer Nature B.V
• Subjects: Ambient temperature; Angular pressing; Annealing; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Copper; Copper industry; crystallization; Crystallography and Scattering Methods; Deformation; Diffraction; Equal channel angular pressing; Extrusion; Extrusion rate; Grain refinement; Grain size; Hardness; Hardness tests; Light diffraction; light microscopy; Materials Science; Mechanical properties; Microhardness; Polymer Sciences; pressing; Recrystallization; Solid Mechanics; Stability analysis; Strain; Thermal stability; X-ray diffraction; X-rays; Equal Channel Angular Pressing; Static Recrystallization; Strain Path; Extrude Material; High Pressure Torsion
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-011-5768-1

Substructural characteristics of Cu (99.97%) were examined after the Twist channel angular pressing (TCAP) process carried out at ambient temperature. Grain refinement efficiency and resulting thermal stability were evaluated after three passes with respect to utilization of various strain paths. Results were obtained using light microscopy and X-ray diffraction methods; Mechanical properties of extruded materials were also tested. Thermal stability was studied after application of three annealing cycles. Based on the findings, Bc route is the most efficient strain path with respect to the grain refinement; higher speed of extrusion (10 mm/s) corresponds with suppression of the static recrystallization. Measured strength, obtained after three passes (route A ), achieved values around 440 MPa homogeneously along the cross section of the extruded material. Homogeneity of deformation was also confirmed by micro-hardness tests. The grain size, determined after three passes, averaged out 1.2 μm. Application of TCAP (three passes) brought markedly homogeneous deformation throughout the processed sample in comparison with classical ECAP process.