宏观石墨颗粒增强工业纯铝金属基复合材料位错阻尼机制的研究

运用空气加压渗流技术制备了宏观石墨颗粒增强的工业纯铝金属基复合材料, 在25～400 ℃温度范围和频率为0.5、1.0和3.0 Hz条件下在多功能内耗仪上测量了材料的内耗和相对动力学模量; 用透射电子显微镜对材料的微观结构进行了观察。依据内耗测量和微观分析研究了宏观石墨颗粒增强工业纯铝金属基复合材料的位错阻尼行为。结果表明, 在频率0.5～3.0 Hz范围内, 复合材料的阻尼与致密工业纯铝的阻尼相比较, 阻尼性能提高2～3倍。复合材料阻尼能力随着石墨颗粒体积分数的增加而增加, 但相对动力学模量在减小, 材料的位错阻尼是一种重要的阻尼机制。

Study on Dislocation Damping Mechanism of Macroscopic Graphite Particulates Reinforced Commercially Pure Aluminum Metal Matrix Composites

Macroscopic graphite (Gr) particulates reinforced commercially pure aluminum (Al) metal matrix composites (MMCs) were prepared by air pressure infiltration process. The internal friction (IF) and relative dynamic modulus were measured by multifunction internal friction apparatus (MFIFA) at frequencies of 0.5, 1.0 and 3.0 Hz in the temperature range of 25～400 ℃. The microstructure analysis was performed using transmission electron microscopy(TEM). Dislocation damping behavior of the macroscopic graphite particulates reinforced commercially pure aluminum MMCs was studied based on the IF measurement and microstructure analysis. The results showed that in the frequency range of 0.5～3.0 Hz damping performance of the composite was raised 2～3 times compared to that of compact commercially pure aluminum. With the increase of volume fraction of graphite particles, the damping capacity increases while the dynamic modulus decreases. Dislocation damping is an important damping mechanism of materials.