摘要
目的 基于镁合金塑性变形难度大的问题,明确挤压速度对镁合金变型材微观组织的影响规律,为高性能镁合金材料设计研发提供理论基础和实际案例。方法 采用不同的挤压速度对Mg-1.0Mn合金进行挤压,得到镁合金棒材;采用金相显微镜、扫描电子显微镜、透射电子显微镜等微观组织检测方法对Mg-1.0Mn合金挤压后的组织进行观察,通过拉伸试验分析合金的力学性能演变规律,并利用施密特定律对不同组织状态的Mg-1.0Mn合金塑性变形机制进行分析。结果 挤压速度对Mg-1.0Mn合金的组织和力学性能有显著影响。在1 m/min的挤压速度下变形后,Mg-1.0Mn合金具有较细的晶粒结构,平均晶粒尺寸为1.5μm;而在10 m/min的挤压速度下变形后,Mg-1.0Mn合金呈现出较大的晶粒结构,平均晶粒尺寸为2.2μm。10 m/min挤压速度下的样品具有较弱的基面织构,最大极密度为5.559。挤压速度升高,可有效弱化基面织构,有效激活塑性变形过程中的基面滑移,提升加工硬化率和塑性伸长率。10 m/min挤压速度下的Mg-1.0Mn合金断裂伸长率高达52.9%。结论 在较低的挤压速度下可以获得较细的晶粒,其织构较强,力学性能表现为屈服强度高、塑性低;当挤压速度较高时,能够有效弱化基面织构,激活更多的基面滑移协调塑性应变,材料具有较好的加工硬化效果,表现出较高的塑性。
Based on the challenge of plastic deformation in magnesium alloys,the work aims to elucidate the impact of extrusion speed on the microstructure of magnesium alloy deformation materials,providing a theoretical foundation and practical examples for the design and development of high-performance magnesium alloy materials.Mg-1.0Mn alloy was extruded at various speed to obtain magnesium alloy bars.Microstructural detection methods such as optical microscopy,scanning electron microscopy,and transmission electron microscopy were used to observe the microstructure of the extruded Mg-1.0Mn alloy.Tensile tests were conducted to analyze the mechanical property evolution of the alloy,and Schmid's Law was applied to investigate the plastic deformation mechanisms of the Mg-1.0Mn alloy in different microstructural states.The extrusion speed had a significant impact on the microstructure and mechanical properties of the Mg-1.0Mn alloy.After deformation at the extrusion speed of 1 m/min,the Mg-1.0Mn alloy exhibited a finer grain structure with an average grain size of 1.5μm,whereas deformation at 10 m/min resulted in a larger grain structure with an average grain size of 2.2μm.Samples prepared at the extrusion speed of 10 m/min displayed a weaker basal texture with a maximum polar density of 5.559.The increase in extrusion speed effectively weakened the basal texture,activated basal slip during plastic deformation,enhanced work hardening rates,and increased plastic elongation.The Mg-1.0Mn alloy prepared by extrusion at 10 m/min exhibited a fracture elongation of up to 52.9%.Lower extrusion speed yields finer grains with stronger textures and mechanical properties characterized by high yield strength and low plasticity.At higher extrusion speed,the basal texture is effectively weakened,allowing for more basal slip to coordinate plastic strain,resulting in better work hardening and higher plasticity in the material.
作者
廖鸿歆
彭鹏
刘青
朱利
刘思然
廖雪松
杨华楠
杜波
陈远富
LIAO Hongxin;PENG Peng;LIU Qing;ZHU Li;LIU Siran;LIAO Xuesong;YANG Huanan;DU Bo;CHEN Yuanfu(Chongqing Hongyu Precision Industry Group Co.,Ltd.,Chongqing 402760,China;School of Metallurgy and Power Engineering,Chongqing University of Science and Technology,Chongqing 401331,China)
出处
《精密成形工程》
北大核心
2026年第3期28-35,共8页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(52301133)
重庆市科学技术局项目(CSTB2025YITP-QCRCX0017,CSTB2025NSCQGPX0203)
中国博士后科学基金(2023M730276)
中国科协青年人才托举工程(YESS20210415)。
关键词
镁合金
挤压
晶粒结构
织构
基面滑移
Mg alloy
extrusion
grain structure
texture
basal slip
