Influence of Substrate Temperature on Microcracks Formation in Plasma-Sprayed Yttria-Stabilized Zirconia Splats

摘要

YSZ molten droplets created by plasma spraying were deposited on the YSZ substrate preheated to different temperature from 75°C to 1000°C. The results showed that there is little change in crack spacing when substrate temperature is less than about 740°C, and a significant increase in crack spacing from 3.54 μm at 740°C to 10.91 μm at 1000°C was observed. A simple qualitative model was proposed on the basis of the origin of thermal stresses to explain the influence of substrate initial temperature on crack density characterized by crack spacing. The analysis indicates that the results can be ascribed to the changes in tensile stress and splat/substrate adhesion resulting from changes of substrate initial temperature.