Laue microdiffraction characterisation of as-cast and tensile deformed Al microwires

ABSTRACT

Single-crystalline cast aluminium microwires with a diameter near 15 $\mu \mathrm{m}$ are characterised by Laue microdiffraction. A microwire in the as-cast condition exhibits a misorientation below $1^{\circ }$ over a length of 500 $\mu \mathrm{m}$. The measured density of geometrically necessary dislocations is low, $<{10}^{12}$ m⁻², though local maxima up to one order of magnitude higher are found. After tensile deformation to failure, the dislocation density is significantly increased in microwires that have mostly deformed in single slip ($\approx 2\times {10}^{13}$ m⁻²), and yet higher when deformation has occurred by multiple slip ($\approx 6\times {10}^{13}$ m⁻²). In deformed single slip oriented microwires, the streaking directions of Laue spots show that dislocations are stored (though not exclusively) on the primary slip system. Results are consistent with a deformation mechanism governed by rotating, likely single-arm, sources.

KEYWORDS:

• X-ray diffraction
• dislocation structures
• plastic deformation
• tensile testing
• microplasticity

Acknowledgments

The authors thank Dr Kurt Schenk for single-crystal X-ray diffraction measurements.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Swiss National Science Foundation (Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung) under grant number #200020_156064.