New Investigation on the High Temperature Capability Limits of APS YSZ Thermal Barrier Coatings at ~1500°C: Preliminary Laser-Rig Testing Results

The objective of this present work is to obtain preliminary data to check the validity of the current 1300 °C upper temperature limit of atmospheric plasma sprayed (APS) YSZ thermal barrier coatings (TBCs). To accomplish this objective, optimized YSZ coating systems were sprayed onto CMSX-4 substrate pucks and their thermal cycling performance was evaluated using a laser rig. Test samples were operated under a temperature gradient of 1500 °C at the coating frontside and 1000 °C at the substrate backside. Two heating-cooling sequences were applied: 5 min of heating and 2 min of cooling for 1000 cycles and 1 h of heating and 2 min of cooling for 10 cycles. In both cases, no TBC failures were observed.