Towards durable thermal barrier coatings with novelmicrostructures deposited by solution-precursor plasma spray

The feasibility of a new processing method—solution precursor plasma spray (SPPS)—for the deposition of ZrO2-based thermal barrier coatings (TBCs) with novel structures has been demonstrated. These desirable structures in the new TBCs appear to be responsible for their improved thermal cycling life relative to conventional plasma-sprayed TBCs. Preliminary results from experiments aimed at understanding the SPPS deposition mechanisms suggest that nanometer-scale particles form in the plasma flame, followed by their deposition by sintering onto the substrate in the intense heat of the plasma flame. The SPPS method, which offers some unique advantages over the conventional plasma-spray process, is generic in nature and can be potentially used to deposit a wide variety of ceramic coatings for diverse applications.