Porous spheres enabling excellent high-temperature abradability and long lifetime for abradable seal coating

Low hardness and high abradability are often required for abradable seal coating (ASC) to protect the blade tip of gas turbines and aeroengines. However, the low bonding strength often lead to spallation failure. In this paper, a novel abradable seal coating with thin-wall porous spheres was designed and prepared. Results show that this coating has both a low hardness of 48.6 HR15Y and a high bonding strength of 25.4 MPa. The abradability and erosion resistance of this coating are 4 times and 63 times higher than reported metal-based coatings. In addition, no surface densification occurs after incursion due to the novel abradable mechanism of crushing of thin-wall sphere. This demonstrates the coating can retain excellent abradability during service and have a long life-time. The combination of durable excellent abradability and adhesive strength contribute to a long lifetime required by next-generation gas turbines and aeroengines towards higher efficiency and reliability.

Automated summary

A novel abradable seal coating with low hardness and high bonding strength was successfully designed and prepared. This coating has significantly higher abradability and erosion resistance compared to metal-based coatings, and can retain excellent abradability and have a long lifetime during service.