Abstract: A vibration reduction method by hard coating was proposed to improve the working reliability of mistuned blisks (integrally bladed disks)， and the mistuned blisk with depositing NiCoCrAlY+YSZ hard coating on both sides of the blades was taken as an example to conduct the vibration investigation. Firstly， the ROM (reduced-order model) of the hard-coated blisk， which can improve the computational efficiency under the premise of ensuring the computational precision， was established by using an improved fixed-IDSMSM (fixed interface dynamic stiffness modal synthesis method). Secondly， the modal analysis of the hard-coated blisk was achieved based on the proposed ROM， and the results were compared with those of the FOM (full-order FEM). Finally， the influence of hard coating on mistuned blisks was studied. The results revealed that the NiCoCrAlY+YSZ hard coating has a good damping effect on mistuned blisks， and can suppress remarkably the resonant response of mistuned blisks.

Key words: mistuned blisk, hard coating, reduced-order model, damped vibration reduction