【作者】 彭博；

【导师】 耿洪滨；

【作者基本信息】 哈尔滨工业大学 ， 空间材料与加工（专业学位）， 2016， 硕士

【摘要】 蜂窝结构有大量的直通孔,渗透流通性好,有较大的开口度,在众多领域有很广泛的应用前景。然而传统的制备方法蜂窝结构连接强度不高,材料的力学性能、热电性能不好,高温性能差,这是因为传统制备方法大多数是金属薄板加工成波纹状,焊接或粘结成蜂窝状,接头处应力集中产生薄弱地带,导致性能差。3D打印技术是一种快速成型技术,这种技术不会产生焊缝等应力集中点,而且不受材料的形状限制,可以轻易制备出复杂结构的材料,很适合作为制备蜂窝结构的工艺。聚乳酸材料在3D打印工艺上有很广泛的应用前景,但是由于脆性大、结晶性能差,严重限制了它的应用。本课题针对碳纳米管增强聚乳酸基复合材料,获得了试样蜂窝几何形状软件设计、原料熔融共混制丝以及3D打印成形一体化工艺,成功制备了蜂窝单元结构试样和哑铃型拉伸试样;利用SEM、XRD、拉曼光谱分析仪、红外光谱分析仪等技术分析碳纳米管增强聚乳酸基复合材料线材微观组织结构,探讨了碳纳米管增强聚乳酸基复合材料性能与其组织结构的关系。通过拉曼光谱分析仪碳纳米管的分子结构进行研究,发现1598cm-1处的峰为G峰,代表的是晶体碳特征峰,为C-C键伸缩振动产生的E2g振动模式。1340cm-1处的峰为D峰,代表的是sp3状态下的碳原子。IG:ID=0.70,这个比值比较大,表示碳原子的缺陷比较少。试验与分析结果表明,制备温度越低,碳纳米管增强聚乳酸基复合材料的拉伸性能与压缩性能越好;实验温度越低,碳纳米管增强聚乳酸基复合材料的拉伸性能与压缩性能越好。除此之外,聚乳酸碳纳米管复合材料在温度超过50℃时,力学性能变的很差,开始流变。通过SEM对PLA/CNTs复合材料的物相组织以及断口进行观察,结合界面分析和断口形貌研究复合材料的断裂机制,发现复合材料断裂主要出现在碳纳米管团聚区域,也是导致其力学性能的下降主要原因。更多还原

【Abstract】 Honeycomb structure exist lot of straight hole, great permeability, major opening degree, has a broad application prospect in many fields. However the traditional preparation methods of cellular structure connection strength is not enough, the material mechanical properties, thermoelectric performance is not too much, high temperature performance is poor, this is because most of the traditional preparation method is as corrugated sheet metal processing, welding or bonding into a honeycomb, weak zone of stress concentration, joint lead to poor performance. 3d printing is a kind of rapid prototyping technology, the technology will not produce the stress concentration, such as weld and is not restricted by the shape of the material, with a complex structure can be easily prepared materials, is very suitable to serve as the process of preparation of honeycomb structure.Polylactic acid materials on the 3d printing technology has a broad application prospect, but the brittleness, poor crystallization performanceseverely limits its application. This topic for carbon nanotubes reinforced polylactic acid based composite material, the sample cell geometry software design, raw material melt blending silk, and the integration of 3 d printing technology, the successful preparation of the sample cell structure and dumbbell tensile samples;Using SEM, XRD, Raman spectrum analyzer and infrared spectrum analyzer and so on technical analysis of carbon nanotubes reinforced polylactic acid composite material wire rod and microstructure of carbon nanotubes are discussed enhanced polylactic acid composite material performance and its organizational structure. Preparation of the test and analysis results show that the lower the temperature, carbon nanotube enhanced the tensile property of polylactic acid based composite material and the better the performance of compression; The experiment temperature is lower, carbon nanotube enhanced the tensile property of polylactic acid based composite material with compression performance, the better.Through SEM of PLA/CNTs composites phase and fracture observation, combined with the interface analysis and fracture morphology research fracture mechanism of composite materials, composite material fracture mainly appeared in the region of the carbon nanotubes together, also led to a decline in its mechanical properties.更多还原