Deformation behaviour of ultrafine grained Mg–7Gd–5Y–1.2Nd–0.5Zr alloy under high strain rates

ABSTRACT

The mechanical behaviour of Mg–7Gd–5Y–1.2Nd–0.5Zr (wt. %) alloy with ultrafine grains was measured by split Hopkinson pressure bar method under the strain rates of 1000, 1500, and 2000 s⁻¹ at room temperature. Dynamic tests were carried out along extrusion direction (ED), transverse direction (TD), and normal direction (ND). The results demonstrated that the flow stress increased with the increase of strain rate, showing a positive strain rate strengthening effect. There was no obvious anisotropy in dynamic compression along ED, TD, and ND, which was caused by rare earth elements and multi-pass deformation. This led to the adoption of plastic deformation mode dominated by non-basal slip and participated by tension twinning.

KEYWORDS:

• Magnesium alloys
• texture
• deformation mechanism
• tension twinning
• slip
• Schmid Factor

Acknowledgement

Thank Professor Zhang Kui, General Research Institute for Nonferrous Metal, for providing Mg–7Gd–5Y–1.2Nd–0.5Zr Magnesium Alloy Sheet for this article.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Pingli Mao http://orcid.org/0000-0002-9007-8551

Additional information

Funding

This work was supported by Surface of the State Natural Science Fund Projects (No. 51571145), City of Ningbo ‘science and technology innovation 2025’ major special project (new energy vehicle lightweight magnesium alloy material precision forming technology) (No. 2018B10045), National Natural Sciences Foundation of China (No. 51504153), Doctoral Scientific Research Foundation of Liaoning Province (No. 20170520033) and Innovation Talent Program in Sciences and Technologies for Young and Middle-aged Scientists of Shenyang (No. RC180111).