Li6.75La3Zr1.75Nb0.25O12增强的Cu基微振动敏感型高阻尼复合材料的制备和阻尼性能研究

基于Li_(6.75)La_3Zr_(1.75)Nb_(0.25)O_(12)(LLZNO)陶瓷材料的近室温高阻尼特性并与金属Cu复合,设计和制备了高阻尼LLZNO/Cu复合材料,并采用多功能内耗仪和显微硬度测量仪对复合材料的阻尼性能和力学性能进行了评价.研究结果表明:与相同制备工艺的纯Cu基体材料相比,LLZNO/Cu复合材料的阻尼性能和硬度值均有显著提高,其中,陶瓷颗粒质量分数为30%的LLZNO/Cu复合材料的阻尼峰值高达0.050,比纯Cu阻尼值提高近25倍,硬度值也从纯Cu试样的59MPa提高到近91MPa.进一步的阻尼-振幅依赖性测试表明,即使应变振幅降低到10×10~(-6),LLZNO/Cu复合材料的阻尼性能也基本保持不变,表现出典型的微振动敏感特性,其机制起因于应力作用下LLZNO陶瓷内高浓度Li离子迁移扩散诱导的能量耗散.

Preparation and Damping Properties of Li6.75La3Zr1.75Nb0.25O12 Particulate Reinforced Cu-based Microvibration Sensitive High Damping Composites

A novel Li6.75La3Zr1.75Nb0.25O12 (LLZNO) reinforced Cu matrix composite is designed and prepared based on the extraordinary damping capacity of LLZNO ceramic at room temperature,and the damping and mechanical properties were evaluated by multi-functional internal friction apparatus and microhardness measurement,respectively.The results indicate that compare with pure Cu material,the damping capacity and hardness of LLZNO/Cu composites are significantly improved.The damping peak for the 30％ LLZNO/Cu Composites can be up to 0.050,which increases nearly 25 times than that of pure Cu materials with the same preparation route,and the hardness value increases from 59MPa pure Cu sample to nearly 91MPa after LLZNO addition.Further investigation related with damping and strain amplitude evidences that even the amplitude is reduced to 10 × 10-6,the damping performance of LLZNO/Cu composites also remain unchanged,which exhibits a typical micro-vibration-sensitive characteristics,and the corresponding mechanism is associated with the energy dissipation induced by the diffusion process of high concentrations Li ions in LZNO ceramic under periodical stress.