Abstract
In order to achieve better knowledge of the thermal barrier coatings (TBCs) by supersonic atmospheric plasma spraying (SAPS) process, an experimental study was carried out to elaborate the physicochemical properties of particles in-flight during the SAPS process. One type of commercially available agglomerated and sintered yttria-stabilized-zirconia (YSZ) powder was injected into the SAPS plasma jet and collected by the shock chilling method. The YSZ particles’ in-flight physicochemical properties during the SAPS process, including melting state, morphology, microstructure, particle size distribution, element composition changes, and phase transformation, have been systematically analyzed. The melting state, morphology, and microstructure of the collected particles were determined by scanning electron microscopy (SEM). The particle size distribution was measured by a laser diffraction particle size analyzer (LDPSA). Element compositions were quantitatively analyzed by an electron probe X-ray microanalyzer (EPMA). Additionally, the X-ray diffraction (XRD) method was used to analyze the phase transformation. The results showed that the original YSZ powder injected into the SAPS plasma jet was quickly heated and melted from the outer layer companied with breakup and collision-coalescence. The outer layer of the collected particles containing roughly hexagonal shaped grains exhibited a surface texture with high sphericity and the inside was dense with a hollow structure. The median particle size had decreased from 45.65 to 42.04 μm. In addition to this, phase transformation took place, and the content of the zirconium (Zr) and yttrium (Y) elements had decreased with the evaporation of ZrO2 and Y2O3.
Highlights
Thermal barrier coatings (TBCs), which can provide thermal insulation to hot components of engines to protect them from corrosion and oxidation at high temperatures, play an important role in advanced gas-turbine and diesel engines [1,2,3]
Characterization of the O-AS Powders and C-AS Particles particles after the supersonic atmospheric plasma spraying (SAPS) plasma jet exhibited a smoother surface with high sphericity (Figure 4a) due to theCharacteristics surface of the of being are immediately byThe the overall high temperature of the SAPS
O-ASpowder powder injected into plasma jet quickly was quickly heated and melted from the injected into thethe plasma jet was heated and melted from the outer outer layer companied with breakup and collision-coalescence
Summary
Thermal barrier coatings (TBCs), which can provide thermal insulation to hot components of engines to protect them from corrosion and oxidation at high temperatures, play an important role in advanced gas-turbine and diesel engines [1,2,3]. Liu et al [11] used the Box–Behnken Design experimental method to analyze the effect of spray parameters on the average velocity and surface temperature of La2 Ce2 O7 particles in-flight and their influence on microstructure and mechanical properties. The key to this system is a novel SAPS gun with a Laval nozzle and internal feedstock injection mode, which means the feedstock particles can be heated and accelerated adequately with no limitation to the melting temperature of the sprayed materials, and it has greater advantage in fabricating high performance ceramic, cermet, or metallic coatings than APS. The YSZ particles in-flight physicochemical properties including melting state, morphology, microstructure, particle size distribution, element composition changes, and phase transformation were investigated in detail during the SAPS process.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
