Hall-Petch relationship in Mg alloys: A review

Huihui Yu¹，Yunchang Xin¹，Maoyin Wang²，Qing Liu¹

1. School of Materials Science and Engineering, Chongqing University2. Institute of Materials, China Academy of Engineering Physics

摘 要：Grain refinement could effectively enhance yield strength of Mg alloys according to the well-known Hall-Petch theory. For decades, many studies have been devoted to the factors influencing the HallPetch slope（k） in Mg alloys. Understanding the factors influencing k and their mechanisms could offer guidance to design and produce high-strength Mg alloys through effective grain refinement hardening. A review and comments of the past work on the factors influencing k in Mg alloys are presented. Results of these previous investigations demonstrate that the value of k in Mg alloys varies with texture, grain size,temperature and stain. The influence of texture and grain size on k is found to be an essential result of the variation of deformation mode on k value. Without the variation of deformation modes, it is revealed that texture could also impose a significant effect on k and this is also summarized and discussed in this paper. The reason for texture effect on k is analyzed based on the mechanism of Hall-Petch relationship.In addition, it is found in face-centered cubic（fcc） or body-centered cubic（bcc） metals that boundary parameters（boundary coherence, boundary energy and boundary diffusivity） could strengthen twinning or slips to a different extent. Therefore, the role of boundary parameters is also extended into the k values in Mg alloys and discussed in this paper. In the end, we discuss the future research perspective of Hall-Petch relationship in Mg alloys.

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