球磨能量对机械合金化 Cu-Cr/CNT混合纳米复合材料制备的影响

摘要

为了研究在两种不同的介质中球磨能量对碳纳米管(CNTs)分散的影响，在3种不同球磨能条件下，采用湿磨和干磨法制备了 Cu−Cr/CNT 混合纳米复合材料。利用 X 射线衍射技术评估了复合材料的结构演变和固溶变形，利用扫描电子显微镜和透射电子显微镜表征了复合材料的显微组织，并采用显微硬度试验测试了其力学性能。其平均晶粒尺寸范围为20~63 nm，与球磨介质和球磨能有关。CNTs 的分散与球磨能呈函数关系。FESEM 像和显微硬度测试结果表明，与干磨法相比，湿磨法更有利于 CNTs 的分散。在高球磨能下湿磨法对制备均质混合纳米复合材料更有利，对 CNTs 的损坏最小，而损坏小且分散较好的 CNTs 有利于获得较高的显微硬度。与晶粒尺寸变化相比，CNTs 的分散和损坏对硬度的影响更大。%Production of Cu−Cr/carbon nanotube (CNT) hybrid nano-composite by wet and dry milling processes at three different levels of milling energy was investigated in order to study the effect of milling energy in two different media on dispersion of CNTs, and preparation of the nano-composite. The structural evolution and solid solution formation were evaluated by X-ray diffraction technique. The microstructure was characterized by scanning electron microscopy and transmission electron microscopy. Also, the mechanical properties were measured by microhardness test. The mean crystallite size was in the range of 20−63 nm depending on milling medium and energy. CNTs dispersion is a function of milling energy. According to FESEM images and microhardness results, it can be concluded that wet milling is more applicable in dispersing CNTs homogeneously in comparison to dry milling. It was also found that wet milling at higher milling energies can be a beneficial method of producing the homogeneous hybrid nano-composite with the least damages introducing on CNTs because of the higher microhardness which can be attributed to better dispersion of less damaged CNTs. Compared with crystallite size changes, CNTs dispersion and damages were considerably more effective on hardness.