Segmented Thermal Barrier Coatings for ID and OD Components Using the SinplexPro Plasma Torch

Abstract

Thermal barrier coatings (TBCs) with high thermal strain tolerance and erosion resistance are commonly applied onto the inner and outer diameters of hot sections of gas turbine engine components. In this work, strain tolerant, segmented TBCs with a variety of crack densities and porosities were developed using the SinplexPro cascaded torch. Design of experiments were carried out to study the effect of process variables such as plasma power, powder feeding rate, spraying distance and surface speed on the coating microstructure and properties. Optimized process parameters for the segmented coating microstructures at shorter spray distance (<75mm) and longer spray distance (>114mm) are achieved, which are targeted for spraying inner diameter and outer diameter engine components, respectively. The plasma torch hardware life was evaluated by torch cycle duration runs. Examples of highly strain tolerant TBCs onto the ID and OD engine components were demonstrated, highlighting the wide versatility and process range of the SinplexPro.