【作者】 邱利；

【导师】 张金中；

【作者基本信息】 中国石油大学 ， 机械设计及理论， 2008， 硕士

【摘要】 当今社会对机械设备、零件的耐磨性的要求越来越高,复杂的工况下材料的耐磨损性能逐渐受到重视。因此寻找一种高耐磨低摩擦系数的涂层成为了现在研究的热点。碳纳米管是一类新型碳材料,是由单层或多层石墨片卷曲而成的中空无缝管状纳米结构。由于碳纳米管的结构特性类似石墨,以及密度小、强度与硬度高的特点,因此碳纳米管将会是性能优良的润滑剂,并具有良好摩擦学性能的强化材料。本文采用碳纳米管作为增强体,对碳纳米管/钴钨涂层的制备工艺和涂层性能进行研究。在钴钨合金沉积液的基础上添加不同含量的碳纳米管,制备出碳纳米管/钴钨复合涂层,探讨了电流密度、碳纳米管的加入量对涂层组织、厚度及硬度的影响以及搅拌、温度、PH值、钴盐含量对电沉积此涂层的影响。本试验对碳纳米管采用酸处理与球磨的方法进行预处理,使得碳纳米管没有明显的团聚现象,具有较好的分散性。试验结果表明:当电流密度为4A/dm2、采用手动搅拌与空气搅拌相结合的方式,在PH值在5~6可获得组织和性能良好的涂层。采用QUANTA200扫描电镜对此涂层的表面形貌分析表明:复合涂层组织比较致密,几乎无微裂纹,通过金相显微镜对碳纳米管复合涂层的组织分析表明复合涂层表面晶粒细化程度明显。通过EDVX能谱分析,碳元素含量明显增高,间接说明碳纳米管被包覆在涂层中。采用MH-3型显微硬度计测定涂层硬度,结果表明:沉积液中碳纳米管加入量在2g/L,对涂层的硬度有明显的增加,但随着碳纳米管加入量的增大,涂层硬度随之下降。这些结果向我们说明适当含量的碳纳米管在复合涂层中的均匀分布对涂层起到了弥散强化。对2g/L碳纳米管复合涂层进行摩擦磨损试验,其摩擦系数明显降低,表明碳纳米管的加入能有效降低摩擦系数。更多还原

【Abstract】 Nawdays the society request the mechanical devices have more and more high wear resistant, and the the material wear resistant performance under the complex operating mode has been paid more attention.Therefore looking for one kind of the coatings which has high wear-resisting low friction coefficient to become the hot spot in the present studies. The carbon nanometer tube is a kind of new carbon material. This nanometer structure is hollow and Seamless tubular structure, which is composed of single layer or the multilayer curling flake of graphite. Because the structure characteristic of carbon nanometer tubes similar with graphite, and which has smaller density, higher intensity and higher hardness characteristic. Therefore the carbon nanometer tubes could be the fine performance lubricant, and will be the strengthened material with good firctional performance. This article uses the carbon nanometer tubes as strengthened body, carries on studies the CNTs\CoW coating preparation craft and the coating performance.Added the different carbon nanometer tubes content in the cobalt tungsten alloy deposition fluid foundation, prepares CNTs\CoW compound coating, discussed the current density and the content of carbon nanometer tubes influence for the quantity of the coating organization, thickness and degree of hardness as well as the agitation, the temperature, the PH value influence to the deposit this coating performance.This experiment uses the acid treatment and the ball grinding method to a carbon nanometer tube carries on the pretreatment, which made the carbon nanometer tubes not have obvious reunion phenomenon and have the good dispersivity. The test result indicated that, when the current density is 4A/dm2, selects the method which the manual agitation and the air agitation unifies, PH value.in 5~7 may obtain the good organization and the performance coating Uses QUANTA200 SEM to analysis superficial appearance of the coating indicated that the compound coating organization relative compaction, nearly has the micro crackles, the degree of superficial crystal grain refinement is obvious. Uses EDVX energy dispersive spectrometer to analyse the coating ingredient, the carbon element content obvious got higher, which explains that carbon nanometer tubes indirectly by hosted grain in coating. Uses the MH-3 microhardness scale determination degree of hardness of the coating, which result indicated: the content of carbon nanometer tube that supplement in the bath is 2g/L, which has the obvious increase to the coating degree of hardness. But with the increasing of the carbon nanometer tubes content , hardness of the coating decreased. Simultaneously, as a result of the carbon nanometer tubes fine self lubrication ability, which plays the anti-friction role in the friction attrition process. Added 2g/L of carbon nanometer tubes in the composite coating for friction and wear testing, the friction coefficient was reduced, that the addition of carbon nanotubes can effectively reduce the coefficient of friction, wear-resistant coatings improve performance.Which resort indicated that the friction and attrited performance of CNTs/CoW compound coating is superior to ordinary cobalt tungsten coating.更多还原