镍涂层短碳纤维增强AZ91D镁基复合材料的界面特征和阻尼性能
发布时间：2018-12-18 06:36
【摘要】：使用表面化学镀镍的短碳纤维为增强体、AZ91D粉为基体金属,用粉末冶金法和热挤压工艺制备镁基复合材料,用SEM、TEM-EDS、拉伸和动态热机械分析(DMA)等手段表征其微观形貌、界面结构、力学性能和阻尼性能,研究了金属镍涂层短碳纤维对AZ91D镁基复合材料的界面和阻尼性能的影响。结果表明,碳纤维在复合材料中分布均匀,沿着挤压方向定向排列;镍涂层改善了碳纤维与AZ91D基体之间的润湿性;不同频率的应变谱和G-L特征线都表明:复合材料的阻尼机制,除了位错之外还有其他机制;随着应变频率的提高复合材料的阻尼机制由以界面滑移为主转变为以位错为主。随着温度的升高涂层碳纤维增强镁基复合材料的阻尼容量增大,在250~300℃出现一个阻尼峰。随着频率的提高阻尼峰值的温度移向高温,表现出热激活弛豫过程的特征,根据Arrhenius公式计算出其热激活能(H)为3.448 e V。
[Abstract]:Magnesium matrix composites were prepared by powder metallurgy and hot extrusion using short carbon fibers coated with nickel on the surface as reinforcement and AZ91D powder as matrix metal. SEM,TEM-EDS, was used to prepare magnesium matrix composites. Tensile and dynamic thermomechanical analysis (DMA) were used to characterize the microstructure, interface structure, mechanical properties and damping properties of AZ91D magnesium matrix composites. The effects of short carbon fibers coated with nickel on the interface and damping properties of AZ91D magnesium matrix composites were studied. The results showed that carbon fiber distributed uniformly in the composites and arranged along the extrusion direction, and the wettability between carbon fiber and AZ91D matrix was improved by nickel coating. The strain spectra and G-L characteristic lines at different frequencies show that the damping mechanism of composites is not only dislocation, but also the damping mechanism of composites is changed from interfacial slip to dislocation with the increase of strain frequency. With the increase of temperature, the damping capacity of the coated carbon fiber reinforced magnesium matrix composites increases, and a damping peak appears at 250 鈩，
本文编号：2385502
[Abstract]:Magnesium matrix composites were prepared by powder metallurgy and hot extrusion using short carbon fibers coated with nickel on the surface as reinforcement and AZ91D powder as matrix metal. SEM,TEM-EDS, was used to prepare magnesium matrix composites. Tensile and dynamic thermomechanical analysis (DMA) were used to characterize the microstructure, interface structure, mechanical properties and damping properties of AZ91D magnesium matrix composites. The effects of short carbon fibers coated with nickel on the interface and damping properties of AZ91D magnesium matrix composites were studied. The results showed that carbon fiber distributed uniformly in the composites and arranged along the extrusion direction, and the wettability between carbon fiber and AZ91D matrix was improved by nickel coating. The strain spectra and G-L characteristic lines at different frequencies show that the damping mechanism of composites is not only dislocation, but also the damping mechanism of composites is changed from interfacial slip to dislocation with the increase of strain frequency. With the increase of temperature, the damping capacity of the coated carbon fiber reinforced magnesium matrix composites increases, and a damping peak appears at 250 鈩，
本文编号：2385502
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