Microstructure and Properties of Magnesium Alloy Bar during Radial Forging-extrusion Forming Process

ZOU Jingfeng; GUO Xingchen; SUN Dong; ZHU Yanchun; LI Yitao; HE Zhiqiang; GAO Feiyang

doi:10.3969/j.issn.1674-6457.2025.11.018

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Journal of Netshape Forming Engineering ›› 2025, Vol. 17 ›› Issue (11) : 190-200. DOI: 10.3969/j.issn.1674-6457.2025.11.018

Light Alloy Forming

Microstructure and Properties of Magnesium Alloy Bar during Radial Forging-extrusion Forming Process

ZOU Jingfeng^1,2,*, GUO Xingchen^1,3, SUN Dong¹, ZHU Yanchun^1,3, LI Yitao^1,2, HE Zhiqiang^1,3, GAO Feiyang^1,3

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Abstract

The work aims to realize the simultaneous improvement in strength and ductility for ZK60 magnesium alloy bars through an integrated radial forging and extrusion process. Finite element simulations via Deform software were employed to analyze the macroscopic stress distribution and strain gradient evolution during both radial forging and subsequent hot extrusion. The radial forging and hot extrusion experiment with large-scale billets was conducted to investigate the microstructural evolution and mechanical properties of bar stocks after composite process treatment to reveal the effect mechanism of macroscopic stress on microstructure and properties. The radial forging effectively fragmented the coarse as-cast microstructure, producing remarkable grain refinement along the axial direction while generating a distinct radial grain size gradient from surface to center. Numerical simulations correlated this graded microstructure with the corresponding strain gradient, additionally revealing the formation of a strong basal texture in the subsurface region. Following high-ratio extrusion (25∶1), the grains were further refined and the texture intensity was weakened, resulting in a typical fibrous texture. Compared with as-cast bars, the bars processed by radial forging-extrusion exhibited substantially enhanced mechanical properties, with tensile strength increasing from 208 MPa to 400 MPa, yield strength from 84 MPa to 263 MPa, and elongation from 8.5% to 23.5%. The radial forging-extrusion process can effectively improve the microstructural homogeneity of ZK60 magnesium alloy bars, achieving a synergistic enhancement of strength and plasticity, which is attributed to the combined effects of grain refinement, second-phase strengthening, and dislocation strengthening.

Key words

magnesium alloy / radial forging / hot extrusion / microstructure / texture

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ZOU Jingfeng, GUO Xingchen, SUN Dong, ZHU Yanchun, LI Yitao, HE Zhiqiang, GAO Feiyang. Microstructure and Properties of Magnesium Alloy Bar during Radial Forging-extrusion Forming Process[J]. Journal of Netshape Forming Engineering. 2025, 17(11): 190-200 https://doi.org/10.3969/j.issn.1674-6457.2025.11.018

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Funding

National Natural Science Foundation of China (52205400, 52375363); Fundamental Research Program of Shanxi Province (202203021212321); The Authors Gratefully Acknowledge the National Key Research and Development Program (2024YFB3714303); Shanxi Provincial Science & Technology Achievements Transformation Guidance Program (202404021301041)