喷嘴结构对等离子喷涂制备Mo涂层组织性能的影响

Influence of Nozzel Structure on Microstructure and Performance of Plasma Sprayed Mo Coatings

等离子喷涂Mo及Mo基复合材料作为减摩抗磨涂层广泛应用于航空航天、船舰、汽车等领域。本文采用直喷嘴和拉瓦尔喷嘴在A3钢上分别制备了Mo涂层,分析比较了两种不同喷嘴结构条件下Mo涂层的微观组织、物相、涂层结合强度以及耐干磨损和浸油摩擦性能。结果表明,采用两种喷嘴结构都制备了连续完整的Mo涂层,相比于采用拉瓦尔喷嘴,直喷嘴制备涂层过程中粒子速度更高,氧化较少,制备的涂层更致密、结合强度更高、耐干磨损性能更优异,而拉瓦尔喷嘴制备的涂层表面孔隙储油效果更好,浸油摩擦系数更小。

Plasma sprayed Mo and Mo-based composites have been widely applied in the aerospace, vessel and automobile industry as friction reduction and antiwear coatings. In this paper,molybdenum coatings fabricated by straight tube nozzel and Laval nozzel have been prepared by palsma spraying tecnique.Microstructure, phase composition, bonding strength, dry wear resistant and oill immersion friction coeficient of the two kinds of coatings have been charactrized,compared and analyzed. Results show that integrited and continuous molybdenum coatings have been successfully fabricated via both kinds of nozzels. But the coatings prepared by straight tube nozzel exhibit higher density, higher bonding strength,better dry wear resisitance due to higher particle velocity and lower oxidation level. The coatings fabricated by Laval nozzel,however, have a lower oill immersion friction coeficient owing to the ＇oill tanker＇ provided by its surface holes.