表面微结构在大气和水环境下的摩擦学特性研究

发布时间：2018-05-29 19:59

本文选题：钛合金 + 微细电火花加工　；参考：《南京航空航天大学》2011年硕士论文

【摘要】：本课题来源于基金项目:NSFC-广东省联合基金重点项目(U0934004)、教育部“新世纪优秀人才支持计划”项目(NCET-10-0068)、教育部博士点基金博导类项目(20093218110026)、江苏省自然科学基金重点项目(BK2010074)、流体传动及控制国家重点实验室开放基金项目(GZKF201009)、机械传动国家重点实验室开放基金项目(SKLMTKFKT201005)。本文利用微细电火花切割技术和微细电火花成形技术在钛合金表面制备了沟槽、网纹微结构;利用激光打标技术在钛合金表面和超声电机定子表面制备了凹坑型阵列;采用增强型磁控阴极电弧镀膜沉积系统在钛合金微结构表面分别制备了CrN和DLC薄膜。最后在载荷为3N,滑移速度为0.4m/s时,将微结构表面、微结构/薄膜表面在去离子水环境下与Si3N4小球对磨,研究其摩擦学特性。同时初步研究了制备凹坑微结构的超声电机定子表面的摩擦学特性。本文获得的主要工作和结论如下: 一、通过不同面积率的正方形和菱形微结构的摩擦学特性研究发现,宽度为0.2mm的正方形和菱形微结构表面在面积率为30%时,显示出比较好的减摩特性,宽度为0.25mm的正方形和菱形微结构表面在面积率为10%时显示出较好的减摩特性。通过沟槽微结构表面的正交试验可以得出:面积率对沟槽微结构的摩擦学特性影响最大,沟槽的深度影响最小。凹坑微结构表面的正交试验结果表明凹坑的直径对摩擦因数影响最大,而凹坑阵列的面积率是凹坑微结构表面的磨损量和小球磨损率的主要因素。通过网纹微结构的正交试验,可以得出宽度是影响网纹微结构表面的稳态摩擦因数的主要因素,在网纹角度为45度,间宽比为10时取得最优效果。二、微结构/CrN薄膜改性表面摩擦因数的跑合期加长,沟槽、网纹微结构/CrN薄膜改性的稳态摩擦因数和所对应的小球磨损率都要低于或接近于光滑CrN薄膜表面,而凹坑微结构/CrN薄膜改性表面的稳态摩擦因数和小球磨损率要高于光滑CrN薄膜表面。沟槽、网纹微结构/DLC薄膜改性表面的摩擦因数跑合期要比凹坑微结构/DLC薄膜改性表面的要短,随着滑移距离的增加,三种微结构/DLC薄膜改性表面的稳态摩擦因数都要低于或接近于光滑DLC薄膜表面,摩擦因数随着微结构宽度的增加而降低。沉积DLC薄膜之后,小球的磨损率相比光滑DLC表面有所增加。三、在超声电机定子头表面制备了凹坑微结构,并通过试验获得定转子之间的摩擦学特性。直径为0.15mm的凹坑表面的摩擦因数最低,稳态摩擦因数在0.45左右,有微结构的表面相对于光滑表面,磨损量要低一些,直径为0.15mm的凹坑表面磨损降低了3倍左右。
[Abstract]:This topic comes from the fund project: NSFC- Guangdong Province Joint Foundation key Project U0934004, Ministry of Education "New Century Outstanding Talent support Program" project NCET-10-0068, Ministry of Education Ph.D. Program Ph.D. Program Project 20093218110026, Jiangsu Natural Science Foundation key Project BK2010074. The open fund project of the State key Laboratory for fluid Transmission and Control is GZKF201009, and the State key Laboratory of Mechanical Transmission is SKLMTKFKT201005. In this paper, micro-EDM and micro-EDM are used to fabricate grooves and mesh microstructures on the surface of titanium alloy, laser marking technology is used to fabricate concave array on the surface of titanium alloy and stator of ultrasonic motor. CrN and DLC thin films were deposited on the microstructure of titanium alloy by enhanced magnetron cathode arc deposition system. Finally, when the load is 3N and the slip velocity is 0.4m/s, the tribological properties of the microstructural surface, the microstructure / thin film surface, and the Si3N4 pellet in deionized water environment are studied. At the same time, the tribological characteristics of the stator surface of the ultrasonic motor fabricated with pit microstructures are studied. The main work and conclusions obtained in this paper are as follows: First, by studying the tribological properties of square and diamond microstructures with different area rates, it is found that the square and rhombus microstructures with width of 0.2mm show better antifriction characteristics when the area ratio is 30. The square and rhombic microstructures with a width of 0.25mm show good antifriction properties when the area ratio is 10. The results of orthogonal experiments show that the area ratio has the greatest influence on the tribological properties of the grooves, and the depth of the grooves has the least effect on the tribological properties of the grooves. The results of orthogonal test show that the diameter of the pit has the greatest influence on the friction coefficient, and the area ratio of the concave array is the main factor of the wear rate of the surface and the wear rate of the ball. Through the orthogonal test of the mesh microstructure, it can be concluded that the width is the main factor affecting the steady friction coefficient of the mesh microstructure surface. The optimum effect is obtained when the mesh angle is 45 degrees and the ratio between width and width is 10:00. Secondly, the running time of the surface friction coefficient of the modified CRN film is lengthened, the steady friction coefficient of the modified CRN film and the wear rate of the corresponding ball are all lower than or close to the smooth surface of the CrN film, and the stable friction coefficient of the modified CRN film and the wear rate of the corresponding ball are lower than or close to that of the smooth CrN film surface. On the other hand, the steady friction coefficient and wear rate of the modified surface of crater microstructure / CRN film are higher than that of smooth CrN film. The friction coefficient of the modified surface of the grooves / mesh microstructures / DLC films is shorter than that of the surface modified by the concave microstructures / DLC films, and with the increase of the slip distance, The steady-state friction coefficient of the modified surface of three kinds of microstructures / DLC films is lower than or close to that of smooth DLC films, and the friction coefficient decreases with the increase of microstructure width. After deposition of DLC film, the wear rate of the ball is higher than that of smooth DLC surface. Thirdly, the pit microstructure was prepared on the stator head surface of ultrasonic motor, and the tribological characteristics between stator and rotor were obtained by experiments. The friction coefficient of the pit surface with diameter of 0.15mm is the lowest, the steady friction coefficient is about 0.45, the wear amount of the surface with microstructure is lower than that of the smooth surface, and the wear of the surface of the pit with diameter of 0.15mm is 3 times lower than that of the smooth surface.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH117.1

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