Abstract

Introducing {10-12} tension twin lamellas has proved to be the most effective strategy to enhance the performance of Mg alloys. Twins can provide the preferential nucleation sites for recrystallization, hence twinning induced grain refinement can result in higher strength material based on Hall-Petch Effect. In addition, twinning can also modify the crystallographic c-axis distribution in wrought Mg alloys resulting in lower plastic anisotropy. Accordingly, in the present work, the twinning evolution in the Mg-0.5Ca (wt.%) alloy at room and cryogenic temperature was critically investigated. The samples were subjected to pre-compression (5%) at room temperature and -150 °C at the strain rate of 10-3 s-1. The microstructural and textural characterization was carried out using OM, SEM and EBSD to emphasize the twinning evolution during compression at room and low temperatures. The local lattice distortion and the localized deformation in terms of Kernel average misorientation (KAM) was also studied. The results revealed the significant grain refinement (13.7 μm 5.61 μm and 6.02 μm of uncompressed and RT, - 150 °C pre-compressed, respectively), where slightly enhanced twinning fraction in the sample compressed at RT was observed. Finally, remarkable increase in the yield strength was noticed in the pre-twinned samples, which was attributed to the twinning-induced grain refinement based on the Hall-Petch relationship.

Highlights

  • Owning to their low density, high specific strength and exceptional recyclability, Magnesium (Mg) and its alloys have been considered as promising candidate for weight reduction in aerospace and automotive industries [1]

  • The results revealed the significant grain refinement (13.7 μm, 5.61 μm and 6.02 μm of uncompressed and room temperature (RT), 150 oC pre-compressed, respectively), where slightly enhanced twinning fraction in the sample compressed at RT was observed

  • The microstructure of as-received Mg-0.5Ca alloy was characterized by electron backscattered diffraction (EBSD) to further investigate the crystallographic orientation and texture characteristics

Read more

Summary

Introduction

Owning to their low density, high specific strength and exceptional recyclability, Magnesium (Mg) and its alloys have been considered as promising candidate for weight reduction in aerospace and automotive industries [1]. The diverse application of Mg alloys has been impeded due to its low intrinsic ductility at room temperature (RT), which can be attributed to the availability of limited slip systems during plastic deformation, owning to its hexagonal close packed (HCP) structure. As per von mises criteria, minimum of five slip systems needs to be available to favor the uniform plastic deformation in polycrystalline material. The plastic deformation in Mg is only governed by the basal {0001}. Published under licence by IOP Publishing Ltd

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call