铝含量对镍铬铝膨润土可磨耗封严涂层性能的影响

Effect of Aluminum Content on the Properties of NiCrAl Bentonite Abradable Sealing Coating

镍铬铝膨润土涂层是一种用于航空发动机、燃气轮机和透平机等封严部位的中高温可磨耗封严涂层。本文采用化学包覆工艺制备了铝含量在3.33 wt.%~4.68 wt.%之间的镍铬铝膨润土粉末,并通过火焰喷涂工艺制备得到镍铬铝膨润土涂层,研究了粉末铝含量对镍铬铝膨润土涂层组织和性能的影响。结果表明:随着粉末中铝含量的增加,涂层的硬度和结合强度呈现上升趋势;当铝含量为4.68 wt.%时,所制备的复合粉末材料经喷涂后,组织均匀性好,涂层硬度为52.84 HR15Y,结合强度为6.63 MPa,在室温及高温下IDR值均小于6%,可磨耗性能优良。

NiCrAl bentonite coating is a kind of medium high temperature abradable sealing coating used for sealing parts of aeroengines,gas turbines and turbines.In this paper,NiCrAl bentonite powder with aluminum content between 3.33 wt.%and 4.68 wt.%was prepared by chemical coating process,and NiCrAl bentonite coating was prepared byflame spraying process.The effect of aluminum content in the powder on the microstructure and properties of NiCrAl bentonite coating was studied.The results showed that with the increase of aluminum content,the hardness and bonding strength of the coating increased.When aluminum content was 4.68wt%,the prepared composite powder exhibited good microstructure uniformity after spraying,the coating the hardness and bonding strength was 52.84 HR15Y and 6.63 MPa,respectively.The IDR value was less than 6%at room temperature and high temperature with excellent abradability.