Yttria-stabilized zirconia thermal barriers sprayed using N2-H2 and Ar-H2 plasmas:: Influence of processing and heat treatment on coating properties

Thermal barrier coatings were produced using both Ar and N-2 as the primary plasma gas. Various aspects of the process and the coatings were investigated. It was found that higher in-flight particle temperatures could be produced using N-2, but particle velocities were lower. Deposition efficiencies could be increased by a factor of two by using N-2 as compared to Ar. Coatings having similar values of porosity, hardness, Young's modulus, and thermal diffusivity could be produced using the two primary gases. The coatings exhibited similar changes (increased hardness, stiffness, and thermal diffusivity) when heat-treated at 1400 degrees C. However, the N-2-Processed coatings tended to have lower values of Young's modulus and thermal diffusivity following such treatment. The results point to the potential advantage, in terms of reduced powder consumption and increased production rate, of using N-2 as compared to Ar as the primary plasma gas for TBC deposition.