CHEN Chuanzhong, LI Shitong, WANG Shuguang＊ CHEN Lubin, PENG Qifeng, YU Jiahong, LEI Tingquan

( Shandong University of Technology ,＊   Shandong Shengjian Mo tor Engine Works)( Harbin Institute of Technology)

Abstract: The microstructure of plasma sprayed Al₂O₃ +TiO₂ NiCrAlY composite ceramic coating w as studied by SEM, TEM, EDAX and XRD etc .The coatings take lamellar st ructure morphology, and the Al₂O₃ +TiO₂ ceramic coating consists of γ-Al₂O₃ , TiO₂ and a small amount of α-Al₂O₃ , As the plasma spraying temperature is higher, the co - melting phenomenon occurred to some ex tent betw een the partily melten Al₂O₃ and most ly melten TiO₂ , and the Al₂O₃ +TiO₂ eutectic microstructure w as formed .Every lamella of Ni based alloy consist s of Ni based solid solut ion and γ′phase ( Ni₃Al) w hich dispersely dist ributed in Ni based solid solution, and the microst ructure betw een the lamellae w as o xide films fo rmed during the spraying .The f ine mechanical bonding interface was formed betw een the coatings .The adoptio n of bonding bo ttom coating relieved st ress flake phenomenon wi th the coatings .

Keywords:  Al₂O₃ +TiO₂ , composite ceramic coating, plasma spraying, microst ructure