碳基复合薄膜抗月尘损伤设计及其摩擦学行为研究

发布时间：2018-01-13 10:08

本文关键词：碳基复合薄膜抗月尘损伤设计及其摩擦学行为研究　出处：《兰州交通大学》2016年硕士论文　论文类型：学位论文

【摘要】：空间月尘环境是人类月球探索经常或必须面对的特殊环境。目前,航天器系统中的许多机动部件的可靠性严重受到月尘的威胁。类金刚石薄膜(diamond-like carbon films,简称DLC薄膜)和二硫化钼薄膜因其优异的摩擦学性能而被广泛应用于太空环境,但是,对于该类固体润滑薄膜在月尘环境中的损伤和摩擦学行为的研究鲜有系统工作。本论文基于碳基固体润滑复合薄膜的成分和结构设计,采用中频磁控溅射技术成功制备了不同调质周期的MoS_2/DLC多层固体润滑薄膜。选用航天510所人工模拟合成的月尘作为三体磨粒,系统考察了MoS_2/DLC多层固体润滑薄膜在无尘和月尘环境下的摩擦学性能,明确了载荷、转速、摩擦时长等因素对固体润滑薄膜材料摩擦学性能的影响,深入分析并探讨了MoS_2/DLC多层薄膜在月尘环境中摩擦磨损机制,研究结果表明:1.所制备的MoS_2/DLC多层薄膜表面光滑、粗糙度小,截面均匀致密。通过机械性能和真空摩擦性能对比发现,最优调制周期数为2,即MoS_2/DLC-4L薄膜。2.在真空无尘环境下,MoS_2/DLC-4L薄膜的摩擦系数和磨损率随着转速的增加都呈现出先减小后增加的趋势,而载荷对MoS_2/DLC-4L薄膜的摩擦磨损影响并不显著。在真空月尘条件下,MoS_2/DLC-4L薄膜的摩擦系数在低载(3 N)和高载(10 N)下具有明显的波动,而在中载(5、7 N)下具有稳定的摩擦系数。磨损率无明显规律,但在高载下薄膜失效。在施加载荷为7 N、转速180 r/min时,MoS_2/DLC-4L薄膜的磨损率随摩擦时间的增加呈指数降低的趋势。初始磨损较高是由于表层(MoS_2层)硬度低,易被月尘颗粒刮离;稳定阶段,DLC层作为承载层减缓磨损。3.单层MoS_2薄膜在真空月尘环境下磨损寿命短,这是由于薄膜自身硬度低的缘故;单层DLC薄膜由于黏着效应导致其真空月尘下高摩擦系数。而MoS_2/DLC-4L薄膜在真空月尘环境下不仅具有稳定的摩擦系数(低至0.02),其磨损寿命也大大提高4.在真空月尘环境下,随着摩擦时间的增加,MoS_2/DLC-4L薄膜的磨痕处形成了大量的“脊”层,使得月尘颗粒可以在摩擦界面有效的滚动,实现低摩擦和低磨损。同时,在接触应力作用下,月尘颗粒破碎形成的微纳米颗粒、薄膜材料及磨屑在界面处形成一层复合转移膜,该转移膜的形成也可有效降低摩擦和磨损。
[Abstract]:The space environment is the human lunar exploration lunar special environment or often must face. At present, the reliability of many moving components in spacecraft systems severely dust threats. Diamond film (diamond-like carbon films, referred to as DLC film) and MoS2 film because of its excellent tribological properties and is widely used in the space environment, but for study on the tribological behavior of the rare injury and solid lubricating film in the dust in the environment. The composition and structure of carbon based solid lubricating composite film based on the design of MoS_2/DLC multilayer solid lubrication films prepared by different conditioning cycle medium frequency magnetron sputtering system. The successful selection of space 510 synthetic dust as abrasive, investigated the tribological properties of MoS_2/DLC multilayer solid lubrication film in clean and dust environment, Ming The effect of friction speed, load, long time and other factors on the tribological properties of solid lubricating film materials, deeply analyzes and discusses the MoS_2/DLC multilayer film in friction and wear mechanism in the dust environment, the results showed: 1. the preparation of the MoS_2/DLC multilayer films with smooth surface roughness, small section, uniform and compact. The mechanical performance and vacuum friction performance comparison, the optimal modulation period number is 2, the MoS_2/DLC-4L film.2. in vacuum clean environment, and the wear rate along with the increase of speed presents the trend of first increase and then decrease the friction coefficient of MoS_2/DLC-4L films, MoS_2/DLC-4L films and load on the friction and wear effect is not significant. In the vacuum dust under the condition of friction the coefficient of MoS_2/DLC-4L thin films at low load (3 N) and high (10 N) had obvious fluctuations, and in the load (5,7 N) has stable friction coefficient. The wear rate of ignorance The explicit rules, but in the film under high load failure. In the applied load is 7 N, the speed of 180 r/min, the wear rate of MoS_2/DLC-4L thin films with the friction time increases exponentially decreasing trend. The initial wear is higher due to surface layer (MoS_2 layer) of low hardness, easy to be scraped from the lunar particles; stable stage. The DLC layer as the bearing layer abrasion.3. single-layer MoS_2 film in vacuum dust environment wear short life, this is due to the film itself because of their low hardness; single layer DLC thin films due to adhesion effect leads to high friction coefficient of the vacuum dust. And MoS_2/DLC-4L films in the vacuum dust environment not only has the stable friction coefficient (low to 0.02) and the wear life is also greatly improved in the 4. vacuum dust environment, along with the increase of friction time, grinding marks the formation of a large number of "ridge" layer of MoS_2/DLC-4L films, the lunar particles can roll in friction interface effectively , low friction and low wear. At the same time, the contact stress under the action of micro nano particles formed by crushing dust particles, thin film material and debris to form a layer of composite transfer film on the interface, the formation of the transfer film can effectively reduce friction and wear.

【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V476.3

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