添加CeO_2对MoS_2基复合涂层摩擦学性能的影响

针对MoS_2基复合涂层耐磨性差和承载能力低的问题,以不同含量(质量分数)的CeO_2作为添加剂,采用喷涂法在GCr15钢表面制备MoS_2基复合涂层。利用摩擦磨损试验机和划痕仪分别研究涂层摩擦磨损性能和结合强度,并借助金相显微镜对涂层磨损形貌进行表征。结果表明:添加适量CeO_2可以改善涂层的摩擦磨损性能,其最佳含量为2%,此时摩擦因数和磨损量均最小,分别为0.232和0.011 3 mm~3;同时结合强度从22 N提高到28.29 N。涂层磨损量随载荷的增大而增大;而载荷小于8 N时,涂层的摩擦因数随载荷的增大而减小,当载荷大于8 N时,摩擦因数又有回升趋势。添加稀土后涂层的承载能力有明显提高。未添加稀土时,涂层产生严重剥离,并发生磨粒磨损;添加2%CeO_2后,涂层发生轻微磨粒磨损,耐磨性得到显著提高。

Effects of CeO2 Addition on Tribological Performance of MoS2 Based Composite Coatings

To improve the wear resistance and bearing capacity, MoS₂ based composite coatings with the different concent additive CeO₂ were prepared on the surface of GCr15 steel via spraying process. An tribo-tester and a adhesion tester were used to investigate the tribological properties and the adhesion strength of the coatings. Meanwhile, the worn surfaces of the coatings was characterized by a metallurgical microscope. The results show that the reasonable addition of CeO₂ can improve the tribological properties of the MoS₂ based coatings. The friction coefficient and wear volume show the minimum value of 0.232 and 0.011 3 mm³ under the CeO₂ content of 2%, and the adhesion strength is also improved from 22 N to 28.29 N. With the increase of the load, the wear volume of the coating increases, while the friction coefficient decreases firstly, with a tendency to rise when the load is larger than 8 N. The bearing capacity of the coating is improved obviously with CeO₂ addition. The coatings without CeO₂ addition are severely stripped and abrasive wear occurred. While after the addition of 2% CeO₂, slight abrasive wear occurres on the coating surface and the wear resistance is improved significantly.