三维网络Ti_(2)AlC/Mg基复合材料制备及阻尼性能

Preparation and damping capacity of three-dimensional network Ti_(2)AlC/Mg matrix composites

采用前驱体法制备Ti_(2)AlC多孔陶瓷预制体,通过辅助压力浸渗工艺制备出组织致密的三维网络相互贯通的Ti_(2)AlC/Mg基复合材料。利用扫描电镜和X射线衍射仪分析复合材料的微观组织和物相组成,使用机械振动分析仪测试复合材料阻尼性能。结果表明,复合材料具有宏观上及微观上双尺度的三维网络结构。恒定温度条件下,复合材料在1 Hz和10 Hz测试条件下的最高损耗正切值分别为0.13和0.15,相比于基体AZ91D镁合金分别提高了约30%和67%,其阻尼表现增强。恒定应变条件下,在最高测试温度时,复合材料出现最大损耗正切值。两种测试条件下,复合材料存储模量均高于基体AZ91D镁合金。从内耗值-存储模量二者平衡的角度来看,复合材料不仅具有更宽的应用温度范围,也具有更好的阻尼-强度平衡性。

The Ti_(2)AlC porous ceramic preforms were prepared by precursor method in this paper,and the Ti_(2)AlC/Mg matrix composites with the dense three-dimensional network structure were prepared by auxiliary pressure infiltration process.The microstructure and phase composition of the composites were investigated by scanning electron microscope(SEM)and X-ray diffractometer(XRD),and the damping performance of the composites was tested by vibration analyzer.The results show that,the composites have the two-scale three-dimensional network structure at the macro and micro levels.At the constant temperature,the maximum loss tangent values of the composites are 0.13 and 0.15 at 1 Hz and 10 Hz,respectively,increasing by about 30%and 67%compared with AZ91D,the damping performance is enhanced.Under the constant strain,the composites have the maximum loss tangent value at the highest test temperature.In the two test conditions,both of the storage modulus is higher than that of AZ91D.From the view of the balance between internal friction and storage modulus,the composites not only have the wider application temperature range,but also have the better damping-strength balance.