NiCrAl/Diatomite可磨耗封严涂层制备及性能

分别利用大气等离子喷涂技术制备了Ni/Al粘结底层、火焰喷涂技术制备了NiCrAl/Diatomite可磨耗封严涂层，研究了喷涂距离、送粉速率、火焰气体总流量、喷涂角度和氧燃比等喷涂参数对生长速率和涂层硬度的影响。结果表明，在较低的氧燃比条件下（O₂∶C₂H₂<1.6），随着喷涂距离的增大，涂层生长速率逐渐下降，硬度先保持不变后逐渐上升；当O₂∶C₂H₂>1.6时，涂层的生长速率会随着喷涂距离的增大先增大后减小，硬度随之逐渐下降。随着喷枪对基体相对移动速度的增大，涂层生长速率略微下降，硬度略有上升。气体总流量的增大使得涂层的生长速率明显上升，硬度明显下降。随着送粉量的增大，涂层生长速率明显提高，硬度随之先上升后下降。

Preparation and Properties of NiCrAl/Diatomite Sealing Coatings

The atmospheric plasma spraying (APS) is used to prepare Ni/Al adhering coating, and flame spraying is used to prepare NiCrAl/Diatomite sealing coating. The effects on growth rates and hardness of coating from distance of spraying, powder feeding rate, flame current, spray angle and oxygen-fuel ratio are studied. Result shows that, when the oxygen-fuel ratio is less than 1.6, along with the raise of spraying distance, the coatings growth rate is lower and the hardness goes up after keeps still. When the O₂:C₂H₂ > 1.6, the growth rate goes up first, then goes down, and hardness turns low gradually. Along with the increase of gun moving speed, coatings growth rate goes down a little, while hardness goes up a little. The increase of flow current increases the growth rate and decreases the hardness. Along with the increase of powder feeding rate, the coatings growth rate increases obviously, and the hardness goes up and then down.