Strengthening mechanisms of Al wires processed by equal channel angular torsion drawing

ABSTRACT

This paper reports the microstructure evolution, mechanical properties and strengthening mechanisms of a commercial purity Al alloy (Al 1350) after severe plastic deformation by a novel continuous method called ‘Equal Channel Angular Torsion Drawing (ECATD)’. Electron backscatter diffraction (EBSD) results revealed an inhomogeneous grain refinement including a large fraction of low-angle grain boundaries. After four passes, the microhardness increases from the initial value of 35 HV up to 44 and 62 HV at the centre and near to wire surface, respectively. A combination of high strength and ductility can be achieved based on the results of a Taguchi design of experiment (DoE) for mechanical properties. The strengthening occurs due to increment of the dislocation density, and development of mainly new low-angle grain boundaries.

KEYWORDS:

• Continuous severe plastic deformation
• equal channel angular torsion drawing
• strengthening mechanism
• gradient microstructure
• mechanical properties
• Taguchi DoE
• wires
• Microstructural evolution

Acknowledgements

The authors would like to acknowledge Dr Stefan Mitsche from Institute of Electron Microscopy and Nanoanalysis (FELMI) of Graz University of Technology (8010 Graz, Austria) for performing EBSD measurements.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

C. Sommitsch http://orcid.org/0000-0002-6854-4851