Particle in-flight behavior and its determining the microstructure and mechanical properties of zirconia based thermal barrier coatings

Abstract

Abstract-The present study aims to elaborate the particle inflight behavior during plasma spraying and its significance in determining the microstructure and mechanical properties of plasma sprayed yttria partially stabilized zirconia (YSZ) thermal barrier coatings (TBCs). The as-sprayed YSZ coatings were characterized in terms of the defects (such as pores, unmelted particles and cracks here), hardness and fracture toughness. The results showed that, due to the higher temperature and velocity of in-flight particles in SAPS than that of APS, denser coatings were formed leading to better mechanical properties, including Vickers hardness and fracture toughness. The percentage of defects of microstructure was similar to the temperature and velocity of particles in-flight during plasma spraying. Again, the results were in agreement with that the structural defects had an strongly effect on its mechanical behavior.

Microstructure and Tribological Properties of Fe-Based-Al2O3-B4C Composite Coatings Prepared by High-Velocity Arc Spraying

“…Some of the particles with a higher melting point were unmelted and insufficiently deformed when they hit the substrate surface under the action of high-velocity air pressure. Thus, particles were embedded in their original form in the coating surface during the solidification and stacking process [25,37,38]. At the same time, a faster cooling rate caused the droplets to shrink, limiting the droplets' tendency to spread.…”