磨削加工对纳米结构陶瓷涂层耐磨性能的影响

对磨削加工后的纳米结构陶瓷涂层进行磨损性能试验.磨损试验首先对纳米结构陶瓷涂层Al2O3/13TiO2的圆柱形工件进行外圆磨削加工,然后将各种不同条件下磨削加工后的圆柱工件装夹到立式铣床的主轴上,进行定速、定载荷的磨损性能试验.磨损性能试验时,圆柱工件在旋转的同时与往复运动的长方形氮化硅陶瓷棒进行滑擦,在其圆柱表面形成磨损沟槽.使用扫描电子显微镜和表面轮廓仪对纳米陶瓷涂层的磨损沟槽进行观察与评定,并与传统陶瓷涂层的磨损沟槽进行对比与分析.为进一步揭示纳米陶瓷涂层的磨损机理,使用有限元法对接触区的应力场进行模拟,并分析纳米陶瓷涂层裂纹的形成与扩展.讨论了磨削工艺参数以及涂层晶粒大小对纳米结构陶瓷涂层耐磨损性能的影响.

Wear Performance of Ground Nanostructured Ceramic Coatings

This study investigates the wear performance of ground nanostructured ceramic coatings. In this study, nanostructured Al2O3/13TiO2 coatings were ground under various conditions and subjected to wear tests under given speed and loading conditions. In the wear tests, a ground sample of cylindrical shape was mounted onto the spindle head of a vertical milling machine. The sample was rotated and slid/rolled against a flat Si3N4 ceramic wear bar that traveled back and forth. Wear tracks of the nanostructured ceramic coatings on the cylindrical surface were observed and measured with a scanning electron microscope and a surface profilometer. The result of wear performance of the nanostructured Al2O3/13TiO2 coatings was compared with that of their conventional counterparts. To further investigate wear mechanisms of the coatings, finite element method was used to model the stress fields in the sliding/rolling contact. The information on the stress fields should provide a clue to wear crack initiation and propagation within the coating. Discussion is provided on how the wear performance of the coatings is related to the grinding process parameters and to the grain size of the coating.