【作者】 刘敏；

【导师】 吕振林；

【作者基本信息】 西安理工大学 ， 材料加工工程， 2005， 硕士

【摘要】 本研究采用经改装的销-盘式摩擦磨损试验机,就颗粒尺寸、颗粒级配、合金化、温度和水润滑等对反应烧结SiC材料自配副的摩擦磨损行为与机理的影响进行了较系统的研究,并结合组织分析、X射线衍射分析和磨面SEM观察,分析讨论了反应烧结SiC材料的自润滑性能,为反应烧结SiC陶瓷材料作为密封件以及摩擦副材料的应用和选材提供参考。研究表明,颗粒尺寸和颗粒级配均对反应烧结碳化硅的摩擦磨损产生影响。颗粒尺寸越小及粗细粒子配比为1:1时的反应烧结SiC具有最好的摩擦学性能。在高温条件下,小颗粒尺寸的反应烧结SiC易形成稳定连续的平滑薄膜层,使得摩擦系数和磨损率降低,具有较好的高温自润滑性能;细粉含量多的SiC材料的氧化程度对温度的升高较敏感,亦表现出优良的高温自润滑摩擦磨损性能。在水润滑作用下,反应烧结SiC的摩擦系数和磨损率成倍降低,具有良好的摩擦学性能。反应烧结SiC室温摩擦时的磨损过程以切削为主,随着温度的升高,其磨损方式发生转变且以切削、氧化腐蚀和剥落为主。合金化研究表明,添加一定量的Ti和Mo可改善高温摩擦条件下反应烧结SiC的干摩擦性能。尤其是在600℃时添加Ti的反应烧结SiC表现出了良好的自润滑特性。合金化反应烧结SiC材料在室温摩擦时的磨损以切削为主,300℃时以氧化膜剥落为主,600℃时则以碳化硅粒子的脱落为主。更多还原

【Abstract】 Using the refitted pin-on-disk tribometre, which was used to test the friction and wear of material under different temperatures, the effects of particle sizes, particle distributions, alloying, experimental temperature and water lubricating on the friction and wear behaviors and mechanisms of reaction-bonded silicon carbide (RB-SiC) are systematically studied under the self-mated conditions. Furthermore, by the analyses of microstructures, X-ray diffraction and worn surfaces by SEM, the self-lubricating properties of RB-SiC were discussed also, in order to offer the references for applications as friction pairs and seal materials using reaction- bonded silicon carbide ceramics materials.From above, the results showed that the particle sizes and particle distributions would effect on the friction and wear properties of RB-SiC. Reaction-bonded silicon carbide composite ceramic with fine particles and its distribution of coarse particles and fine particles being 1:1 had good tribological properties and self-lubricating properties at elevated temperature. However, the friction coefficient and wear rate of RB-SiC with fine particle size would be decreased because it was favorable to form a smooth and stable oxidation film on friction surface. With the increase of fine particles content in RB-SiC, it also revealed good high temperature self-lubricating properties because of the increase of its oxidation degree at high temperature. Furthermore, the friction coefficient and wear rateof RB-SiC would be decreased sharply and revealed good tribological properties under water lubricating.The wear mechanism of RB-SiC was dominated by micro-cutting at room temperature. But it was changed from micro-cutting to oxidation fretting and spalling in friction process with the increase of temperature.In the end, one can find that the addition of titanium and molybdenum elements would be improved the dry tribological properties of RB-SiC under the elevated temperature, and the reaction-bonded silicon carbide with titanium behaves good self-lubricating properties at 600℃ especially. As an important result, the wear mechanism of alloying RB-SiC was mostly micro-cutting at room temperature, the spalling of oxidation film at 300℃, and the desquamating of SiC particles at 600℃.更多还原