The Role of Long Period Stacking Ordered Phase in Dynamic Recrystallization of a Mg-Gd-Y-Zn-Zr Alloy during Multi-Directional Forging Process.

Huiling Liu,Siyang Zhang,Wenlong Xu,Yingze Meng,Huisheng Yu,Leichen Jia,Guoqin Wu

doi:10.3390/ma13153290

Huiling Liu, Siyang Zhang + Show 5 more

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https://doi.org/10.3390/ma13153290

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Journal: Materials	Publication Date: Jul 24, 2020
Citations: 9	License type: CC BY 4.0

Affiliation: Jinzhong University, North University of China

Abstract

The Mg–Gd–Y–Zn–Zr alloy containing a long period stacking ordered (LPSO) phase was subjected to multi-pass deformation by means of a multi-directional forging process, and the microstructure evolution and the influence of the LPSO phase on its dynamic recrystallization (DRX) were studied. The results showed that multi-directional forging can effectively refine the grain with the DRX fraction increased, and DRXed grains lead to the decrease of the texture intensity, which can significantly improve the mechanical properties of the alloy. The different morphologies of the LPSO phase have different degrees of promotion relative to DRX behavior. The lamellar LPSO phase with kinks promoted dislocation plugging, where there could be a potential nucleation site for DRX grains. The fragmented lamellar LPSO phase promoted the DRX process through the particle-stimulated nucleation mechanism, and the block-shaped phase was more prone to stress concentration, which promoted DRX. These effects resulted in continuous grain refinement and a more uniform microstructure.

Highlights

That the resources and the environment have become the primary issues for sustainable development, lightweight has become an important development trend in aerospace, automotive, equipment, and other fields [1]
Magnesium alloys have excellent specific strength and specific stiffness, excellent shock absorption performance, high thermal conductivity, electrical conductivity and good shielding, and they have become the first choice as metal structural materials for the lightweight design of various load-bearing components such as various boxes or shells used in automobiles [3]
If high-performance forged blanks are used for subsequent extrusion or processing, the design requirements can be met [5]

Summary

Introduction

That the resources and the environment have become the primary issues for sustainable development, lightweight has become an important development trend in aerospace, automotive, equipment, and other fields [1]. Under such a development background, the pursuit of a high-strength and high-stiffness transmission case structure will inevitably increase the transmission assembly mass, and a lightweight design of the transmission case is the general trend [2]. With the development trend of a lightweight overall structure design, the strength and toughness of boxes or shells need to be higher and higher. In order to obtain higher mechanical properties in Materials 2020, 13, 3290; doi:10.3390/ma13153290 www.mdpi.com/journal/materials

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