金属玻璃基复合材料的微结构效应

Microstructure effect of metallic glass matrix composites

基于自由体积理论和Ramberg-Osgood模型,并利用ABAQUS软件,建立颗粒随机分布代表性体积单元模型,模拟了Ti_(64.5)Zr_(14.5)V_(18.5)Cu_(2.5)颗粒增韧Ti基金属玻璃基复合材料在单轴拉伸状态下的微结构效应,讨论了颗粒的体积分数、团聚数目、长径比、定位取向和界面对金属玻璃韧性的影响。结果表明:提高颗粒体积分数能显著提高复合材料的塑性,但部分牺牲了复合材料的强度;增大颗粒长径比能够增强复合材料的塑性和屈服强度;使颗粒的取向与荷载方向成90°或0°,不仅增强了复合材料的塑性,而且与其他排布相比也增强了复合材料的强度;减少团聚数目至2个以下,能明显减少金属玻璃基复合材料的塑性和强度的损失,使团聚中颗粒与荷载成90°,却能改善复合材料的塑性和强度;在颗粒增韧金属玻璃基复合材料中加入零厚度界面,能观察到在主剪切带上颗粒和基体在界面处脱粘,得到与实验现象更加吻合的结果。通过上述的研究能够很好地理解复合材料的微结构效应,并有利于材料的设计。

Based on the free volume theory and Ramberg Osgood model, a representative volume element model with particles random distribution was established, and the microstructure effect of Ti64.5 Zr14.5 V18.5 Cu2,5 particles toughening Ti-base metallic glass matrix composites under the uniaxial tension, was simulated by ABAQUS code. The effects of particles volume fraction, the number of reunion and aspect ratio, along with particles orientation and interface on the ductility of metallic glass were discussed. Results show that increasing particles volume fraction can improve the plasticity of composites significantly, but at the expense of the part strength of the composites. Increas ing particles aspect ratio can enhance the plasticity and yield strength of composite materials. Making the orientation of particles and the load direction into 90° or 0° not only enhances the plasticity, but also improves the strength of composites compared with the other configuration. Reducing the number of reunion to below two can significantly reduce loss of the plasticity and strength of metallic glass composites, and the particles of reunions and the load at 90°, can improve the plasticity and strength of composites. In particles toughening metallic glass matrix composites with zero interface, particles and matrix debonding in interface in the main shear belt can be observed, according with the experimental phenomena more. The results help to well understand the microstructure effect of the composite materials which is beneficial to the design of the material.