LPSO相对挤压态Mg-Gd系合金再结晶与性能的影响

doi:10.13251/j.issn.0254-6051.2025.11.019

摘要/Abstract

摘要： 以Mg-Gd系合金为研究对象,对其均匀化处理后分别采用水冷与炉冷的方式冷却至室温,随后利用一次热挤压变形得到挤压态试样。利用OM、SEM、TEM及电子万能试验机等对组织和性能进行了表征,分析了LPSO相对合金性能的影响。结果表明,炉冷试样组织中包含大量层片状长周期堆垛有序(LPSO)相,而水冷试样中几乎没有层片状LPSO相生成。热挤压变形后,水冷试样组织中绝大部分由再结晶晶粒构成,仅保留少量的粗大变形晶粒;而炉冷试样呈现双峰晶粒异质结构,即包含大量细小再结晶晶粒与粗大的未再结晶晶粒,同时保留部分层片状LPSO相。与镁基体共格的LPSO相对于晶粒的形核及生长具有抑制作用,这是炉冷试样存在粗大未再结晶晶粒的原因;而层片状LPSO相在挤压过程中发生破碎、扭折、弯曲,导致LPSO相与镁基体产生非共格界面,从而在这些位置有利于晶粒再结晶,这是炉冷试样存在细小再结晶晶粒的原因。较挤压态水冷试样,挤压态炉冷试样的室温抗拉强度和屈服强度提高,断后伸长率降低,分别为377.1 MPa、324.8 MPa和16.0%。LPSO相强化、双峰异质结构强化以及细晶强化是炉冷试样获得优异综合力学性能的主要原因。

关键词: Mg-Gd系合金, 均匀化处理, 冷却速率, 长周期堆垛有序相, 再结晶, 力学性能

Abstract: Extruded specimens of Mg-Gd series alloy, after homogenizing, and then water quenching and furnace cooling to room temperature, respectively, were prepared by one-time hot extrusion deformation. The microstructure and properties were characterized by means of optical microscope, scanning electron microscope, transmission electron microscope, and electronic universal testing machine, and the effect of LPSO phase on the alloy properties was analyzed. The results show that the microstructure of the furnace-cooled specimen contains a large number of lamellar long-period stacking ordered (LPSO) phases, while almost no lamellar LPSO phase is formed in the water-quenched specimen. After hot extrusion deformation, the microstructure of the water-quenched specimen is mostly composed of recrystallized grains, with only a small amount of coarse deformed grains remaining. In contrast, the furnace-cooled specimen exhibits a bimodal heterogeneous grain structure, it contains a large number of fine recrystallized grains and coarse unrecrystallized grains, while retaining some lamellar LPSO phases. The LPSO phase coherent with the magnesium matrix has an inhibitory effect on the nucleation and growth of grains, which is the reason for the presence of coarse unrecrystallized grains in the furnace-cooled specimen. However, the lamellar LPSO phase undergoes fragmentation, kinking and bending during the extrusion process, leading to the formation of incoherent interfaces between the LPSO phase and the magnesium matrix. Consequently, these locations are favorable for grain recrystallization, which is the reason for the presence of fine recrystallized grains in the furnace-cooled specimen. Compared with the as-extruded water-quenched specimen, the as-extruded furnace-cooled specimen exhibits higher room-temperature tensile strength and yield strength, but lower elongation, which are 377.1 MPa, 324.8 MPa, and 16.0%, respectively. LPSO phase strengthening, bimodal heterogeneous structure strengthening, and grain refinement strengthening are the main reasons for the excellent comprehensive mechanical properties of the furnace-cooled specimen.

Key words: Mg-Gd series alloy, homogenizing, cooling rates, LPSO phase, recrystallization, mechanical properties

中图分类号:

TG146.2

陈立珂, 张志鹏. LPSO相对挤压态Mg-Gd系合金再结晶与性能的影响[J]. 金属热处理, 2025, 50(11): 133-140.

Chen Like, Zhang Zhipeng. Effect of LPSO phase on recrystallization and properties of as-extruded Mg-Gd series alloy[J]. Heat Treatment of Metals, 2025, 50(11): 133-140.

参考文献

[1] Yang Jingran, Zhu Zhiqi, Han Shijie, et al. Evolution, limitations, advantages, and future challenges of magnesium alloys as materials for aerospace applications[J]. Journal of Alloys and Compounds, 2024, 1008: 176707.
[2] Bai Jingying, Yang Yan, Wen Chen, et al. Applications of magnesium alloys for aerospace: A review[J]. Journal of Magnesium and Alloys, 2023, 11(10): 3609-3619.
[3] Wang G G, Weiler J P. Recent developments in high-pressure die-cast magnesium alloys for automotive and future applications[J]. Journal of Magnesium and Alloys, 2023, 11(1): 78-87.
[4] Xu Tiancai, Yang Yan, Peng Xiaodong, et al. Overview of advancement trend on magnesium alloy[J]. Journal of Magnesium and Alloys, 2019, 7: 536-544.
[5] 王海清, 李建波, 王毅涛, 等. Mg-Gd-Zn高稀土镁基复合材料的变形行为[J]. 材料热处理学报, 2024, 45(7): 34-43.
Wang Haiqing, Li Jianbo, Wang Yitao, et al. Deformation behaviors of Mg-Gd-Zn based high rare-earth magnesium matrix composites[J]. Transactions of Materials and Heat Treatment, 2024, 45(7): 34-43.
[6] Zhang Jinghuai, Liu Shujuan, Wu Ruizhi, et al. Recent developments in high-strength Mg-RE-based alloys: Focusing on Mg-Gd and Mg-Y systems[J]. Journal of Magnesium and Alloys, 2018, 6: 277-291.
[7] 毕广利, 冉吉上, 满宏生, 等. 挤压Mg-Y-Ni-Co合金的显微组织、加工性能及塑性变形行为[J]. 材料导报, 2024, 38(21): 230-237.
Bi Guangli, Ran Jishang, Man Hongsheng, et al. Microstructure, processing properties and plastic deformation behavior of an extruded Mg-Y-Ni-Co alloy[J]. Materials Reports, 2024, 38(21): 230-237.
[8] 王旭, 黄元春, 王强, 等. 异步轧制对Mg-Gd-Y-Zn-Zr板材组织、织构和性能的影响[J]. 稀有金属, 2023, 47(7): 934-941.
Wang Xu, Huang Yuanchun, Wang Qiang, et al. Microstructure, texture and mechanical properties of Mg-Gd-Y-Zn-Zr sheet with different rolling speed[J]. Chinese Journal of Rare Metals, 2023, 47(7): 934-941.
[9] Zheng Jie, Chen Zhe, Yan Zhaoming, et al. Preparation of ultra-high strength Mg-Gd-Y-Zn-Zr alloy by pre-ageing treatment prior to extrusion[J]. Journal of Alloys and Compounds, 2022, 894: 162490.
[10] Yamasaki M, Sasaki M, Nishijima M, et al. Formation of 14H long period stacking ordered structure and profuse stacking faults in Mg-Zn-Gd alloys during isothermal aging at high temperature[J]. Acta Materialia, 2007, 55(20): 6798-6805.
[11] 罗宇伦, 杨鸿, 董志华, 等. Mg-TM-RE系镁合金中LPSO相的研究进展[J]. 中国有色金属学报, 2024, 34(5): 1429-1452.
Luo Yulun, Yang Hong, Dong Zhihua, et al. Research progress of LPSO phase in Mg-TM-RE alloy[J]. The Chniese Journal of Nonferrous Metals, 2024, 34(5): 1429-1452.
[12] Kim J K, Sandlöbes S, Raabe D. On the room temperature deformation mechanisms of a Mg-Y-Zn alloy with long-period-stacking-ordered structures[J]. Acta Materialia, 2015, 82: 414-423.
[13] Zhou Xiaojie, Liu Chuming, Gao Yonghao, et al. Improved workability and ductility of the Mg-Gd-Y-Zn-Zr alloy via enhanced kinking and dynamic recrystallization[J]. Journal of Alloys and Compounds, 2018, 749: 878-886.
[14] Xu Chao, Nakata Taiki, Qiao Xiaoguang, et al. Effect of LPSO and SFs on microstructure evolution and mechanical properties of Mg-Gd-Y-Zn-Zr alloy[J]. Scientific Reports, 2017, 7: 40846.
[15] Wu Jing, Ikeda Ken-ichi, Shi Qi, et al. Kink boundaries and their role in dynamic recrystallisation of a Mg-Zn-Y alloy[J]. Materials Characterization, 2019, 148: 233-242.
[16] Wang Xu, Zhao Yongxing, Li Ming, et al. Achieving enhanced mechanical properties of extruded Mg-Gd-Y-Zn-Zr alloy by regulating the initial LPSO phases[J]. Materials Science and Engineering A, 2024, 917: 147411.
[17] Ding Ning, Du Wenbo, Li Xudong, et al. Deformation mode and strengthening mechanism of Mg-Gd-Er-Zn-Zr alloy with different LPSO morphology[J]. Journal of Alloys and Compounds, 2024, 992: 174524.
[18] Zhou Jianxin, Yang Hong, Xiao Jianfei, et al. Optimizing LPSO phase to achieve superior heat resistance of Mg-Gd-Y-Zn-Zr alloys by regulating the Gd/Y ratios[J]. Journal of Materials Research and Technology, 2023, 25: 4658-4673.
[19] Wu Xia, Pan Fusheng, Cheng Renju, et al. Effect of morphology of long period stacking ordered phase on mechanical properties of Mg-10Gd-1Zn-0.5Zr magnesium alloy[J]. Materials Science and Engineering A, 2018, 726: 64-68.
[20] Liang Dahui, Chen Mincong, Li Chuanqiang, et al. Mechanical property and anisotropy of as-extruded Mg-Zn-Y-Mn alloys with different volume fraction of long-period stacking ordered(LPSO) phase[J]. Journal of Rare Earths, 2024, 42: 2259-2269.
[21] Yin Wujun, Briffod Fabien, Shiraiwa Takayuki, et al. Mechanical properties and failure mechanisms of Mg-Zn-Y alloys with different extrusion ratio and LPSO volume fraction[J]. Journal of Magnesium and Alloys, 2022, 8: 2158-2172.
[22] 田凯凯, 李全安, 陈晓亚, 等. 热处理对Mg-8Gd-3Y-1.5Zn-0.6Zr合金组织与力学性能的影响[J]. 金属热处理, 2022, 47(11): 54-58.
Tian Kaikai, Li Quanan, Chen Xiaoya, et al. Effect of heat treatment on microstructure and mechanical properties of Mg-8Gd-3Y-1.5Zn-0.6Zr alloy[J]. Heat Treatment of Metals, 2022, 47(11): 54-58.
[23] Zhao Xueting, Shang Shan, Zhang Tianxiang, et al. Phase-field simulation on the influence of cooling rate on the solidification microstructure of Mg-Gd-Y ternary magnesium alloy[J]. Rare Metal Materials and Engineering, 2020, 49(11): 3709-3717.
[24] Cai Huisheng, Zhang Nannan, Liu Liang, et al. Effects of cooling rate on the microstructure and properties of magnesium alloy-a review[J]. Journal of Magnesium and Alloys, 2024, 12(8): 3094-3114.
[25] Wang Dan, Fu Penghuai, Peng Liming, et al. Development of high strength sand cast Mg-Gd-Zn alloy by co-precipitation of the prismatic β′ and β₁ phases[J]. Materials Characterization, 2019, 153: 157-168.
[26] Zhang Song, Yuan Guangyin, Lu Chen, et al. The relationship between (Mg, Zn)₃RE phase and 14H-LPSO phase in Mg-Gd-Y-Zn-Zr alloys solidified at different cooling rates[J]. Journal of Alloys and Compounds, 2011, 509: 3515-3521.
[27] 黄元春, 王舟, 马尚坤. 均匀化处理对 Mg-9.8Gd-3.5Y-2Zn-0.5Zr合金微观组织的影响[J]. 金属热处理, 2022, 47(10): 1-9.
Huang Yuanchun, Wang Zhou, Ma Shangkun. Effect of homogenization treatment on microstructure of Mg-9.8Gd-3.5Y-2Zn-0.5Zr alloy[J]. Heat Treatment of Metals, 2022, 47(10): 1-9.
[28] Zhou Xiaojie, Liu Chuming, Gao Yonghao, et al. Microstructure and mechanical properties of extruded Mg-Gd-Y-Zn-Zr alloys filled with intragranular LPSO phases[J]. Materials Characterization, 2018, 135: 76-83.
[29] Fu Wei, Dang Pengfei, Guo Shengwu, et al. Heterogeneous fiberous structured Mg-Zn-Zr alloy with superior strength-ductility synergy[J]. Journal of Materials Science & Technology, 2023, 134: 67-80.
[30] Ovid′ko I A, Valiev R Z, Zhu Y T. Review on superior strength and enhanced ductility of metallic nanomaterials[J]. Progress in Materials Science, 2018, 94: 462-540.
[31] Zhu Yuntian, Wu Xiaolei. Heterostructured materials[J]. Progress in Materials Science, 2023, 131: 101019.
[32] Wu Hao, Fan Guohua. An overview of tailoring strain delocalization for strength-ductility synergy[J]. Progress in Materials Science, 2020, 113: 100675.
[33] Yang Xiaodong, Zhou Xiaojie, Yu Shilun, et al. Tensile behavior at various temperatures of the Mg-Gd-Y-Zn-Zr alloys with different initial morphologies of LPSO phases prior to extrusion[J]. Materials Science and Engineering A, 2022, 851: 143634.
[34] Zhang Xiaohua, Shi Yuan, Li Jiaqi, et al. Improving strength-ductility of Mg-8.5Gd-4.5Y-0.8Zn-0.4Zr magnesium alloy due to bimodal LPSO and <c+a> dislocations[J]. Journal of Rare Earths, 2025, 43(4): 832-842.
[35] Zhou Jianxin, Luo Xiaojun, Yang Hong, et al. Introducing lamellar LPSO phase to regulate room and high-temperature mechanical properties of Mg-Gd-Y-Zn-Zr alloys by altering cooling rate[J]. Journal of Materials Research and Technology, 2023, 24: 7258-7268.
[36] Wu Guoqin, Li Zhaocan, Yu Jianmin, et al. Texture evolution and effect on mechanical properties of repetitive upsetting-extruded and heat treatment Mg-Gd-Y-Zn-Zr alloy containing LPSO phases[J]. Journal of Alloys and Compounds, 2023, 938: 168666.[37] Han Yuxiang, Chen Zhiyong, Jiang Yuxuan, et al. Microstructure, deformation and fracture mechanism of Mg-Gd-Y-Zn-Zr alloy with different rolling routes during tension[J]. Materials Science and Engineering A, 2024, 915: 147275.
[38] Zhang Deping, Li Boqiong, Chao Du, et al. Development of low rare-earth containing magnesium alloy with high strength-ductility synergy by engineering nano-spaced lamellae[J]. Journal of Materials Research and Technology, 2023, 27: 7233-7243.
[39] Wu Guoqin, Li Zhaocan, Yu Jianmin, et al. Optimization in strength-ductility of Mg-RE-Zn alloy based on different repetitive upsetting extrusion deformation paths[J]. Materials and Design, 2023, 232: 112114.
[40] Lv Binjiang, Peng Jian, Zhu Lili, et al. The effect of 14H LPSO phase on dynamic recrystallization behavior and hot workability of Mg-2.0Zn-0.3Zr-5.8Y alloy[J]. Materials Science and Engineering A, 2014, 599: 150-159.
[41] Yu Zijian, Xu Chao, Meng Jian, et al. Effects of extrusion ratio and temperature on the mechanical properties and microstructure of as-extruded Mg-Gd-Y-(Nd/Zn)-Zr alloys[J]. Materials Science and Engineering A, 2019, 762: 138080.
[42] Chen Yuanli, Jin Li, Dong Jie, et al. Effects of LPSO/α-Mg interfaces on dynamic recrystallization behavior of Mg_96.5Gd_2.5Zn₁ alloy[J]. Materials Characterization, 2017, 134: 253-259.
[43] Liu Huan, Ju Jia, Yang Xiaowei, et al. A two-step dynamic recrystallization induced by LPSO phases and its impact on mechanical property of severe plastic deformation processed Mg₉₇Y₂Zn₁ alloy[J]. Journal of Alloys and Compounds, 2017, 704: 509-517.
[44] Ramezani S M, Zarei-Hanzaki A, Abedi H R, et al. Achievement of fine-grained bimodal microstructures and superior mechanical properties in a multi-axially forged GWZ magnesium alloy containing LPSO structures[J]. Journal of Alloys and Compounds, 2019, 793: 134-145.