基于分子动力学模拟的铜锆晶体/非晶双相纳米复合材料力学行为

金属玻璃因其较差的室温塑性限制了其广泛应用，因此提升金属玻璃的力学性能、探明金属玻璃的变形机制已经成为当前材料领域的研究热点。采用分子动力学方法研究了晶粒尺寸和分布对晶体/非晶B2-CuZr/CuZr双相复合材料力学行为的影响。研究结果表明，随着纳米晶粒的尺寸增大，复合材料变形模式发生了从相对均匀变形到单一剪切带的局部变形的转变。研究指出，增大纳米晶粒尺寸/体积分数能有效提高复合材料的峰值应力，但除了较小尺寸纳米晶粒模型外，双相复合材料的塑性没有明显增强。此外，相对于交叉排列，纳米晶粒的对齐排列导致了更严重的塑性应变局部化。本文的研究结果对于设计和制备高性能的金属玻璃材料具有重要的参考价值和指导意义。 

Mechanical behavior of copper-zirconium crystal/amorphous dual-phase nanocomposite based on molecular dynamics simulation

The wide application of metallic glass is limited by its poor room temperature plasticity. Therefore, improving the mechanical properties of metallic glass and exploring the deformation mechanism of metallic glass have become the research hotspot in the field of materials. The effects of grain size and distribution on the mechanical behavior of dual-phase nanocrystalline/amorphous B2-CuZr/CuZr composites were studied by molecular dynamics method. The results show that with the increase of the size of nanocrystalline particles, the deformation mode of the composites changes from relatively uniform deformation to local deformation of single shear band. The results also indicate that the peak stress of the composites can be effectively increased by increasing the size/volume fraction of nanocrystals, but the plasticity of the composites is not significantly enhanced except for the smaller size nanocrystalline model. In addition, alignment of nanocrystals leads to more severe plastic strain localization than cross alignment. The results of this paper have important reference value and guiding significance for the design and preparation of high-performance metallic glass materials.