模拟服役条件下镍-石墨涂层的可磨耗性研究

Investigation on Abradability of Nickel-Graphite Coatings under a Simulated Service Condition

火焰喷涂镍石墨封严涂层广泛应用于高压压气机前对开机匣和其他航空发动机零件上,其目的是通过与叶尖或蓖齿之间的磨削控制转子与机匣壳体之间的间隙,从而提高发动机的效率,降低燃油消耗率,可磨耗性是评价封严涂层性能的重要指标之一。根据航空发动机设计的迫切要求,开展了模拟工况下镍-石墨涂层的摩擦磨损试验,并对涂层的可磨耗性进行了深入研究,分析了切削深度、切削速率等因素对涂层可磨耗性能的影响机制。结果表明:在相同叶尖线速度下,切削深度对涂层磨损的影响比切削速率的影响更为显著;镍-石墨涂层在高线速度下的主要摩擦磨损机制是塑性变形和摩擦氧化;环境温度对涂层的摩擦磨损有一定的影响。

Flame sprayed nickel-graphite sealing coatings are widely used on the high pressure compressor(HPC)front start-up box forward case assembly and other aircraft engine parts,with the purpose of controlling the clearance between the rotors and surrounding casing by friction with the blade tips or labyrinth,thus to improve the efficiency of the engine and lower the specific fuel consumption,and the abradability is the one of the most important properties to evaluate the property of the sealing coating.In the present paper,according to the urgent requirements of aeroengine design,the friction and wear test of nickel-graphite coating under simulated working conditions was carried out,the abradability of the coating was deeply studied,and the influence mechanism of cutting depth and cutting rate on the abradability of the coating was analyzed.Results indicated that the effect of incurs depth on wearing of the coating was more significant than that of the incursion rate at the same blade tip linear speed.The dominant friction and wear mechanisms of the nickel-graphite coating at high linear velocity were plastic deformation and friction oxidation.The environmental temperature had a certain influence on the friction and wear of the coating.