喷涂轨迹对齿柱表面耐磨涂层沉积均匀性的影响

Influence of Spraying Trajectory on Uniformity of Wear-resistant Coating Sprayed on Teeth Column

设计和采用不同的喷涂轨迹,通过超音速火焰喷涂技术在铝齿柱表面制备了WC-10Co4Cr涂层,利用金相显微镜(OM)、SEM和显微硬度测试等进行了涂层的微观组织观测和厚度、硬度均匀性分析。结果表明:涂层致密,与基体结合非常好。涂层厚度和硬度分布不均匀,齿槽底沉积率高,厚度偏大,啮合面和齿顶位置厚度在160～210μm之间,数值分散性较小,齿槽底涂层硬度低,HV0.3≈700～800,啮合面和齿顶位置涂层硬度高,HV0.3在1150～1300范围内。齿形件的喷涂轨迹参数2 H影响齿顶面、啮合面和齿槽等不同位置的喷涂角度和沉积环境,导致涂层形貌、沉积率和硬度均有差别。2 H=55mm时,不同齿形位置的涂层厚度和硬度分布更均匀,但齿槽底涂层存在孔隙,硬度偏低。

The WC-10Co4Cr coating was prepared using high velocity oxy-fuel flame spraying （HVOF） technology on aluminum tooth cylinder with two different spraying trajectory.The microstructure and thickness and hardness uniformity of the coating were analyzed byOM,SEM and microhardness testing.The results show that the coating has high density and good bonding between the coating and matrix.In different positions of tooth profile,the coating thickness and hardness distribute non-homogeneously.The deposition rate in the bottom of tooth space is high and coating thickness is much larger.The coating on tooth surface and tooth tip is between 160-210 μm in thickness and the values dispersion is small.The coating microhardness,HV0.3,is in the range of 700 to 800 in the bottom of tooth space and in the range of 1150 to 1300 for other positions.The spraying trajectory parameter,2H,affects spray angle and deposition environment when spraying at different positions of tooth,resulting in the different coating morphology,deposition rate and hardness.When 2H=55 mm,the coating thickness and hardness of the different positions are more uniform,but coating in the bottom has some porosity and lower hardness.