摘要
镁合金因其低密度、高比强度和良好的生物相容性等优点，在航空航天、汽车制造及生物医学等领域展现出广阔的应用前景，但其室温塑性差限制了广泛应用。为改善镁合金的塑性变形能力并提高加工性能，本研究采用微观组织分析、力学性能测试与有限元模拟相结合的方法，系统探讨了不同变形温度、应变速率及预变形量对镁合金显微组织演变和力学行为的影响规律。通过对比分析挤压态、退火态和热处理态下AZ31镁合金的拉伸性能，发现适当的热处理工艺可显著提升材料的延伸率；引入等通道转角挤压（ECAP）技术制备超细晶镁合金，结果表明经ECAP处理后，镁合金的屈服强度和均匀塑性应变均得到明显增强。此外，基于晶体塑性理论建立了多尺度本构模型，实现了对镁合金复杂变形过程的有效预测。本研究揭示了镁合金在不同加工条件下的微观组织-性能关系，为优化镁合金成形工艺提供了理论依据和技术支持，创新性地提出了结合热处理与 severe plastic deformation (SPD) 技术改善镁合金综合性能的新思路，拓展了镁合金在工程领域的应用范围。
关键词：镁合金；塑性变形；热处理
Abstract
Magnesium alloys, owing to their low density, high specific strength, and excellent biocompatibility, exhibit broad application prospects in aerospace, automotive manufacturing, and biomedical fields. However, their poor room-temperature ductility limits widespread application. To improve the plastic deformation capability and processability of magnesium alloys, this study systematically investigates the influence of different deformation temperatures, strain rates, and pre-deformation amounts on the microstructural evolution and mechanical behavior of magnesium alloys by combining microstructure analysis, mechanical property testing, and finite element simulation. Comparative analysis of the tensile properties of AZ31 magnesium alloys in extruded, annealed, and heat-treated states reveals that appropriate heat treatment processes can significantly enhance material elongation. The equal-channel angular pressing (ECAP) technique was introduced to prepare ultrafine-grained magnesium alloys, and results indicate that ECAP treatment markedly increases both the yield strength and uniform plastic strain of magnesium alloys. Additionally, a multi-scale constitutive model based on crystal plasticity theory was established, achieving effective prediction of the complex deformation processes of magnesium alloys. This study elucidates the microstructure-property relationship of magnesium alloys under various processing conditions, providing theoretical basis and technical support for optimizing magnesium alloy forming processes. It innovatively proposes a new approach to improving the comprehensive performance of magnesium alloys by combining heat treatment with severe plastic deformation (SPD) techniques, thereby expanding their application range in engineering fields.
Keywords：Magnesium Alloy; Plastic Deformation; Heat Treatment
目 录
摘要 I
Abstract II
一、绪论 1
(一) 镁合金研究的背景与意义 1
(二) 国内外研究现状综述 1
(三) 本文的研究方法与思路 2
二、镁合金塑性变形机制 2
(一) 晶体学基础与位错运动 2
(二) 变形孪生现象分析 3
(三) 温度对塑性变形的影响 3
三、镁合金加工工艺优化 4
(一) 热处理工艺参数研究 4
(二) 成型技术选择与应用 5
(三) 加工缺陷预防措施 5
四、镁合金微观组织演变 6
(一) 变形过程中的相变行为 6
(二) 显微组织特征观察 7
(三) 组织性能关联性研究 7
结 论 9
参考文献 10
镁合金因其低密度、高比强度和良好的生物相容性等优点，在航空航天、汽车制造及生物医学等领域展现出广阔的应用前景，但其室温塑性差限制了广泛应用。为改善镁合金的塑性变形能力并提高加工性能，本研究采用微观组织分析、力学性能测试与有限元模拟相结合的方法，系统探讨了不同变形温度、应变速率及预变形量对镁合金显微组织演变和力学行为的影响规律。通过对比分析挤压态、退火态和热处理态下AZ31镁合金的拉伸性能，发现适当的热处理工艺可显著提升材料的延伸率；引入等通道转角挤压（ECAP）技术制备超细晶镁合金，结果表明经ECAP处理后，镁合金的屈服强度和均匀塑性应变均得到明显增强。此外，基于晶体塑性理论建立了多尺度本构模型，实现了对镁合金复杂变形过程的有效预测。本研究揭示了镁合金在不同加工条件下的微观组织-性能关系，为优化镁合金成形工艺提供了理论依据和技术支持，创新性地提出了结合热处理与 severe plastic deformation (SPD) 技术改善镁合金综合性能的新思路，拓展了镁合金在工程领域的应用范围。
关键词：镁合金；塑性变形；热处理
Abstract
Magnesium alloys, owing to their low density, high specific strength, and excellent biocompatibility, exhibit broad application prospects in aerospace, automotive manufacturing, and biomedical fields. However, their poor room-temperature ductility limits widespread application. To improve the plastic deformation capability and processability of magnesium alloys, this study systematically investigates the influence of different deformation temperatures, strain rates, and pre-deformation amounts on the microstructural evolution and mechanical behavior of magnesium alloys by combining microstructure analysis, mechanical property testing, and finite element simulation. Comparative analysis of the tensile properties of AZ31 magnesium alloys in extruded, annealed, and heat-treated states reveals that appropriate heat treatment processes can significantly enhance material elongation. The equal-channel angular pressing (ECAP) technique was introduced to prepare ultrafine-grained magnesium alloys, and results indicate that ECAP treatment markedly increases both the yield strength and uniform plastic strain of magnesium alloys. Additionally, a multi-scale constitutive model based on crystal plasticity theory was established, achieving effective prediction of the complex deformation processes of magnesium alloys. This study elucidates the microstructure-property relationship of magnesium alloys under various processing conditions, providing theoretical basis and technical support for optimizing magnesium alloy forming processes. It innovatively proposes a new approach to improving the comprehensive performance of magnesium alloys by combining heat treatment with severe plastic deformation (SPD) techniques, thereby expanding their application range in engineering fields.
Keywords：Magnesium Alloy; Plastic Deformation; Heat Treatment
目 录
摘要 I
Abstract II
一、绪论 1
(一) 镁合金研究的背景与意义 1
(二) 国内外研究现状综述 1
(三) 本文的研究方法与思路 2
二、镁合金塑性变形机制 2
(一) 晶体学基础与位错运动 2
(二) 变形孪生现象分析 3
(三) 温度对塑性变形的影响 3
三、镁合金加工工艺优化 4
(一) 热处理工艺参数研究 4
(二) 成型技术选择与应用 5
(三) 加工缺陷预防措施 5
四、镁合金微观组织演变 6
(一) 变形过程中的相变行为 6
(二) 显微组织特征观察 7
(三) 组织性能关联性研究 7
结 论 9
参考文献 10
