烧结聚晶金刚石真空摩擦学性能及其磨损机理研究

发布时间：2018-06-13 16:41

本文选题：聚晶金刚石 + 真空环境　；参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：聚晶金刚石具有与天然金刚石相似的优异摩擦学性能以及超高的硬度,目前广泛应用于加工刀具、石油地质钻探等设备的制造。聚晶金刚石的优异性能为其在空间领域的应用提供了可能,研究真空环境下聚晶金刚石的摩擦学性能具有重要意义。本文采用RM-1型多功能真空摩擦试验机对聚晶金刚石进行真空摩擦学性能测试。对比了聚晶金刚石在不同真空度与大气环境下的摩擦系数、磨损形貌的区别,研究了不同载荷对聚晶金刚石真空摩擦学性能的影响,分析讨论摩擦系数、磨损形貌与所选载荷的联系,并且对比聚晶金刚石与不同对摩材料(Si3N4、Si C、Al2O3和GCr15)在真空环境下的摩擦学性能,分析不同材料在真空环境下对磨聚晶金刚石的磨损机理,还研究了不同真空度环境下聚晶金刚石的摩擦学性能,分析了不同真空度下聚晶金刚石的磨损程度的影响。分析讨论磨损机理,阐明其特殊结构与其在真空环境下摩擦磨损行为的联系。结果表明:(1)聚晶金刚石在真空环境下的摩擦系数远远高于大气环境下。摩擦系数随载荷升高而增大;大气环境下聚晶金刚石在所选取载荷下未出现明显磨损,而在真空环境中有明显的磨损发生,磨损程度随载荷升高而增大。磨损的主要形式是PCD表面金刚石颗粒剥落形成的剥落坑。(2)真空环境中,聚晶金刚石对磨不同材料,摩擦学性能有明显区别。对磨Si C和Si3N4过程中发生黏着效应,前者黏着程度高于后者,且聚晶金刚石表面出现以金刚石颗粒脱落为主的磨损。对磨GCr15过程中,聚晶金刚石表面颗粒剥落并镶嵌到对磨球上,对聚晶金刚石表面形成三体磨损。对磨Al2O3后,聚晶金刚石表面未出现明显磨损。(3)真空度对聚晶金刚石摩擦学性能有显著影响。随着真空度的升高,聚晶金刚石对磨Si3N4的摩擦系数逐渐升高,表面金刚石颗粒脱落越来越严重。(4)真空环境下聚晶金刚石摩擦系数升高的原因是,对磨副表面吸附膜在真空环境中解吸附而导致的越来越严重的黏着效应。真空环境下在所选载荷下摩擦磨损试验后PCD表面金刚石颗粒脱落的原因主要是高的摩擦系数产生的摩擦热导致金刚石颗粒在粘结相Co的催化下出现石墨化。
[Abstract]:Polycrystalline diamond has similar excellent tribological properties and super high hardness as natural diamond, so it is widely used in the manufacture of cutting tools, petroleum geological drilling equipment and so on. The excellent properties of polycrystalline diamond provide the possibility for its application in space field. It is of great significance to study the tribological properties of polycrystalline diamond in vacuum environment. The vacuum tribological properties of polycrystalline diamond were tested by RM-1 multifunctional vacuum friction tester. The friction coefficient and wear morphology of polycrystalline diamond under different vacuum and atmospheric conditions are compared. The effects of different loads on the vacuum tribological properties of polycrystalline diamond are studied, and the friction coefficient is analyzed and discussed. The wear morphology is related to the selected load, and the tribological properties of polycrystalline diamond and Si _ 3N _ 4Si _ 2O _ 3 / Al _ 2O _ 3 and GCr15) in vacuum environment are compared, and the wear mechanism of different materials to the abrasive polycrystalline diamond in vacuum environment is analyzed. The tribological properties of polycrystalline diamond under different vacuum conditions were studied, and the effects of different vacuum degree on the wear degree of polycrystalline diamond were analyzed. The wear mechanism is analyzed and discussed, and the relation between its special structure and its friction and wear behavior in vacuum environment is explained. The results show that the friction coefficient of polycrystalline diamond in vacuum environment is much higher than that in atmospheric environment. The friction coefficient increases with the increase of load, and the wear degree of polycrystalline diamond increases with the increase of load. The main form of wear is the spalling pit formed by the spalling of diamond particles on the surface of PCD. In vacuum environment, the tribological properties of polycrystalline diamond for grinding different materials are obviously different. The adhesion effect occurred in the process of grinding sic and Si _ 3N _ 4, the adhesion degree of the former was higher than that of the latter, and the wear of polycrystalline diamond surface was dominated by diamond particle shedding. In the process of GCr15 grinding, the surface particles of polycrystalline diamond are peeled off and embedded on the grinding ball, and the surface of polycrystalline diamond is worn out in three bodies. After Al _ 2O _ 3 grinding, the surface of polycrystalline diamond has no obvious wear. 3) the degree of vacuum has a significant effect on the tribological properties of polycrystalline diamond. With the increase of vacuum degree, the friction coefficient of polycrystalline diamond to grinding Si _ 3N _ 4 increases gradually, and the friction coefficient of polycrystalline diamond increases in vacuum environment. The adhesion effect of the adsorbed film on the surface of the grinding pair is more and more serious due to its desorption in vacuum environment. The reason why diamond particles on PCD surface fall off after friction and wear test under selected load in vacuum environment is mainly due to the friction heat produced by high friction coefficient which results in graphitization of diamond particles under the catalysis of binder phase Co.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ163

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