二维过渡族金属硫化物及其复合材料的制备表征与摩擦学性能研究

发布时间：2018-10-12 07:46

【摘要】：近几年来,高温、低温、高真空、高负载、强辐射等特殊工况条件下的摩擦磨损对工业生产造成了巨大的能源浪费。正确地使用润滑材料,减少特殊工况条件下机械运动系统中与摩擦磨损相关的机械失效引起了人们的关注。最近,石墨烯及其相关的二维纳米材料(如过渡族金属硫化物)凭借其独特的性能尤其是超薄的厚度和独特的二维平面结构成为了近年来材料研究领域的热点之一,并广泛应用于催化、能量储备和电子器件中。然而,石墨烯与二维过渡族金属硫化物在摩擦学领域应用还处于初级阶段。本论文在参考相关文献成果的基础上,针对日益严重的摩擦造成的能源浪费问题,重点介绍利用二维材料的摩擦学性能来降低摩擦磨损,并对其未来发展进行了展望。本论文的具体内容包括:1,采用表面活性剂辅助的水热法合成MoS_2/石墨烯二维复合材料。采用XRD,SEM,HRTEM和Raman光谱对复合材料的结构进行了表征,验证了产物的形貌和微观结构;探讨了复合材料的形成机理。我们将MoS_2/石墨烯作为液体润滑添加剂,考察其摩擦学性能。结果表明,复合材料表现出了优异的摩擦学性能指标(平均摩擦系数~0.09和磨损率~2.08×10-5 mm3/Nm)。此外,我们考察了所制备的MoS_2/石墨烯复合材料对环氧树脂(E-44)涂层摩擦学性能的影响。结果表明,添加5 wt%的MoS_2/石墨烯复合材料能够有效改善涂层的摩擦磨损性能。2,以商业化的石墨和MoS_2为原料,采用球磨法一步合成MoS_2/石墨烯复合材料。研究了石墨与MoS_2的不同质量比对产物的影响。结果表明,当MoS_2纳米片的含量较高时能够覆盖在石墨片表面,在球磨剥离过程扮演类似胶带的作用来实现石墨烯的剥离。系统考察环氧树脂涂层摩擦学性能随MoS_2/石墨烯复合材料含量变化的关系。结果发现,填充少量的MoS_2/石墨烯复合材料能够有效的降低涂层的摩擦系数,提高涂层的抗磨寿命。对比分析了试验载荷对摩擦学行为的影响。结果表明,随载荷的增加,虽然摩擦系数有所下降,但是磨损率有较大增加。3,以固相烧结合成的NbSe2作为前驱体,采用球磨法合成NbSe2纳米片及其与石墨烯的复合材料。研究了球磨时间对产物形貌的影响。结果表明,随着球磨时间的增加NbSe2在有序堆叠的c轴方向的相关长度将减少,即有利于NbSe2纳米片的剥离。系统考察了添加所制备的二维NbSe2纳米片及其复合材料对环氧树脂涂层摩擦学性能的影响。结果表明,环氧树脂复合涂层的摩擦系数随着NbSe2纳米片含量增加(从0至20%)急剧减少到最低值从0.337至0.062(降低了80%),磨损率也大幅下降;添加少量NbSe2/G可以明显改善环氧涂层的减摩抗磨性能;当NbSe2/G含量较高时,破坏了涂层的连续性,填料与聚合物之间的结合强度降低,从而造成聚合物涂层的摩擦磨损性能降低。
[Abstract]:In recent years, friction and wear under special working conditions such as high temperature, low temperature, high vacuum, high load and strong radiation have caused great energy waste to industrial production. The correct use of lubricating materials to reduce the mechanical failure related to friction and wear in the mechanical motion system under special working conditions has attracted people's attention. Recently, graphene and its related two-dimensional nanomaterials (such as transition metal sulphides) have become one of the hot research fields in recent years because of their unique properties, especially ultra-thin thickness and unique two-dimensional planar structure. And widely used in catalysis, energy storage and electronic devices. However, the application of graphene and two-dimensional transition metal sulfides in tribology is still in its infancy. On the basis of referring to the related literature, this paper focuses on the use of tribological properties of two-dimensional materials to reduce friction and wear in the light of the increasingly serious energy waste caused by friction, and prospects for its future development. The main contents of this thesis are as follows: 1. MoS_2/ graphene two-dimensional composites were synthesized by hydrothermal method assisted by surfactants. The structure of the composites was characterized by XRD,SEM,HRTEM and Raman spectra, the morphology and microstructure of the composites were verified, and the formation mechanism of the composites was discussed. The tribological properties of MoS_2/ graphene as liquid lubricating additive were investigated. The results show that the composites exhibit excellent tribological properties (average friction coefficient ~ 0.09 and wear rate ~ 2.08 脳 10 ~ (-5) mm3/Nm). In addition, the effect of MoS_2/ graphene composite on tribological properties of epoxy resin (E-44) coating was investigated. The results show that 5 wt% MoS_2/ graphene composites can effectively improve the friction and wear properties of the coatings. 2. Commercial graphite and MoS_2 were used as raw materials to prepare MoS_2/ graphene composites by ball milling. The effect of different mass ratio of graphite to MoS_2 on the product was studied. The results show that when the content of MoS_2 nanocrystalline is high, it can cover the surface of graphite sheet and play a similar role as tape in the process of ball-milling stripping to realize the exfoliation of graphene. The relationship between the tribological properties of epoxy resin coating and the content of MoS_2/ graphene composite was investigated systematically. The results show that the friction coefficient of the coating can be reduced and the wear resistance life of the coating can be improved by filling a small amount of MoS_2/ graphene composite. The effect of test load on tribological behavior is compared and analyzed. The results show that with the increase of load, the friction coefficient decreases, but the wear rate increases greatly. 3. Using NbSe2 synthesized by solid phase sintering as precursor, NbSe2 nanochips and their composites with graphene are synthesized by ball milling method. The effect of milling time on the morphology of the product was studied. The results show that with the increase of milling time, the correlation length of NbSe2 in the c-axis direction of orderly stacking will decrease, that is to say, it is advantageous to the stripping of NbSe2 nanocrystals. The tribological properties of epoxy resin coatings were investigated by adding two-dimensional NbSe2 nanochips and their composites. The results showed that the friction coefficient of epoxy resin composite coating decreased sharply with the increase of NbSe2 content (from 0 to 20%) to the lowest value from 0.337 to 0.062 (decreased by 80%), and the wear rate also decreased significantly. When the content of NbSe2/G is high, the continuity of the coating is destroyed and the bonding strength between filler and polymer decreases, which results in the decrease of friction and wear properties of the coating.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB332

【参考文献】