Study on Thermal Shock Performance of Dense Vertically Cracked Thermal Barrier Coatings

The ZrO₂-7%Y₂O₃ powder produced by domestic company was used to make dense vertically cracked (DVC) thermal barrier coatings (TBCs) via the High energy plasma spray system. The influence of preheating temperature of substrates, the thickness of single deposition and spray power on the microstructure of the coatings was studied in detail. The porosity of the thermal barrier coatings prepared by Delta gun was 2.8%-7.3% and bonding strength of the coatings was 20-30MPa. The results demonstrated that the TBCs with DVC structure had excellent thermal shock resistance, and the 1100°C thermal shock lifetime was 206 cycles, which was obviously better than different coating structure by conventional APS (life less than 100 cycles). The mechanism of the failure of the TBCs in the thermal shock process was investigated.