This coating material is a kind of material which compounds metal material and nonmetal material together. Metal material has the performance of high structural strength, high erosion resistance and easy to coat etc. Familiar ones are nickel, copper, chromium, aluminum etc. and their alloys. Nonmetal material’s abradability is strong and has good self-lubricating property. Familiar ones are polyphenyl ester, graphite, diatomaceous earth, bentonite, hexagonal boron nitride etc.
Modern aero-engine adopts gas compressor to supercharge and warming the air. The high temperature compressed air goes into combustor to let the fuel burn adequately is one of the major measures to improve engine power and thermal efficiency. Adopting thermal spraying technology, compressor volute’s surface is sprayed abradable seal coating, and form a pair of abradable seal wear vice with compressor blade tip’s hard coating. In the process of operation, it forms ideal radial air stream gap and acquires maximum differential pressure so that it can improve the power of engine observably, reduce the consumption of aviation gasoline and improve percent of pass of engine once test drive. This is the one of important application achievements of thermal spraying technology in the aeroengine field.
With the compressed air temperature is increasing progressively, the usage temperature of abradable seal coating is increasing from 300 ℃ to 1100 ℃. The maximum temperature of modern abradable seal coating can reach 1350 ℃.
Thermal spraying abradable seal coating technology can be applied in civilian industry field, like gap control of rotating compressed gas parts in compressor industry.
1. Al-si polyphenyl ester 2. Ni-C 3. Ni/diatomaceous earth 4. NiCrAl/BN 5. Y2O3ZrO2-BN