This paper examines the effects of spark plasma sintering (SPS) on flame-sprayed zirconia coatings. It describes how the zirconia layers were produced, treated, and tested. The combination of heating and loading increased coating hardness and adhesion strength by a factor of three and caused a significant reduction in porosity. It also led to phase transformations which, in some cases, had an offsetting effect on coating properties. Paper includes a German-language abstract.