Achieving room temperature superplasticity in the Zn-0.5Cu alloy processed via equal channel angular pressing

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 723; pp. 126 - 133
• Main Authors: Bednarczyk, Wiktor, Kawałko, Jakub, Wątroba, Maria, Bała, Piotr
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 18.04.2018; Elsevier BV
• Subjects: Alloys; Copper; Copper base alloys; Deformation mechanisms; ECAP; Elongation; Equal channel angular pressing; Grain boundaries; Grain size distribution; Mechanical properties; Microstructure; Misalignment; Plastic deformation; Room temperature; Room temperature superplasticity; Strain rate sensitivity; Superplasticity; Temperature effects; Tensile tests; Texture; Zinc; Zinc alloys; Zinc alloys; Room temperature superplasticity; Plastic deformation; ECAP
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2018.03.052

The Zn-0.5Cu alloy was investigated in as-cast, homogenized state and after carrying out equal channel angular pressing four times at room temperature via route BC. Microstructure analysis using light microscopy and SEM/EBSD was performed, as well as tensile tests, misorientation angle distribution and texture analysis. The initial microstructure with the average grain size of 560 µm was refined to a grain size of approx. 1 µm. The obtained microstructure consists of uniaxial grains separated mostly by high angle grain boundaries. Mechanical characterization was performed at strain rates from 2 × 10−6 s−1 to 1 s−1 at room temperature. Ultrafine-grained zinc-copper alloy exhibited 510% elongation with the strain rate sensitivity equal 0.31, which was the first observation of room temperature superplasticity in Zn-Cu alloys. Based on the microstructure, misorientation angle and texture analysis, the main operating deformation mechanisms were distinguished for samples deformed at strain rates from 2 × 10−5 s−1 to 10−1 s−1.