通过等通道角挤压技术获得超细晶组织已成为提高镁合金材料强塑性的重要发展方向。针对等通道角挤压过程中常出现多尺度微观组织的特点，本项目以Mg-Y-Nd合金为研究对象，通过ECAP挤压、低温动态塑性变形、退火热处理等实验制备可控尺寸配比的多尺度材料，测试分析不同尺度晶粒的统计数值和室温力学性能，建立不同多尺度组织超细晶材料的强化模型和塑性模型，研究多尺度微观组织与强塑性耦合关系规律。通过XRD、TEM、EBSD、SEM等手段分析合金塑性变形前后微观组织结构的演变，弄清各尺度晶粒、亚晶粒和孪晶对超细晶Mg-Y-Nd合金强塑性的贡献，探索多尺度微观组织在稀土镁合金塑性变形中的作用机理。本项目的研究成果可为提高镁合金强塑性水平提供理论依据和工艺方法，可为超细晶镁合金塑性变形理论的完善提供参考，具有重要科学意义和学术价值。

Through equal channel angular pressing technology to abtain ultrafine grains has become an important direction of development to improve the strength and plasticity of magnesium alloy materials.According to the characteristics of multi-scale microstructure often appear at the process of equal channel angular extrusion; channel angular pressing,The project use Mg-Y-Nd alloy as the research object.Through the ECAP pressing   and The dynamic plastic deformation at low temperature annealing heat treatment to prepare the controlled size ratio of the multiscale materials,numerical test   of different scale grain statistics analysis and the mechanical properties at room temperature ,build strenghten model and plastic model of different multiscale organization of ultrafine grained materials,study on the relationship of microstructure and strong multi scale plastic coupling law.By XRD, TEM and EBSD analysis, SEM and other means to observe and analyse the plastic deformation of the   microstructure alloy before and after the evolution ,clear the contribution of each scale grain, the subgrain and the twin crystal of ultrafine crystalline Mg-Y-Nd the strong plastic alloy, exploring multi-scale microstructure in rare earth magnesium alloy and the functional mechanism of plastic deformation.The research results of this project can provide theoretical basis and technical method to improve the magnesium alloy strength and plasticity,it can provide reference for the improvement of the deformation theory of ultrafine magnesium alloy plastic, has important scientific significance and academic value.