Nanoindentation creep behavior of grain boundary in pure magnesium

Abstract

Nanoindentation creep tests were performed at the grain boundary and grain interior in pure magnesium. The grain boundary showed a high strain rate sensitivity exponent and was dominated by grain boundary sliding due to the high diffusion rate at the grain boundary. The grain boundary affected the deformation behavior of the area at a distance of 2 µm into the grain interior. On the other hand, the grain interior had a low strain rate sensitivity exponent, because its matrix was too large to be influenced by the grain boundary. The deformation mechanism in the grain interior was determined to be dislocation slip.

Keywords:

• nanoindentation
• magnesium
• grain boundary sliding
• grain boundary

Acknowledgements

The authors are grateful to Ms M. Isaki (National Institute for Materials Science) for her technical help. This study was supported by the JSPS Grant-in-Aid for Young Scientists (B) No. 21760564 (Hidetoshi Somekawa) and Grant-in-Aid for Scientific Research (B) No. 21360347 (Toshiji Mukai).