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.

With the intensification of lunar exploration, the failure risk caused by the adsorption of lunar dust on the spacecraft surface cannot be ignored. Therefore, three types of typical spatial solid lubrication films, namely polytetrafluoroethylene (PTFE), amorphous carbon (a-C) and molybdenum disulfide (MoS ₂ ), were prepared as test samples. Firstly, the surface free energy parameters of the material were measured using a contact Angle measuring instrument. At the same time, atomic force microscopy (AFM) was used to quantify the adhesion of the film samples based on the lunar dust micro-adsorption model. In order to investigate the influence of the test environment, the environmental pressure was adjusted to normal pressure environment and high vacuum environment with a vacuum degree of 10 ⁻⁶  Pa for testing. The results indicate a positive correlation between surface energy and adhesion. As surface energy increases, molecules tend to move closer, forming a stronger attraction and thus enhancing surface adhesion. In addition, AFM was used to measure the adhesion force under atmospheric pressure and vacuum conditions, revealing that parameters measured in atmospheric environment were generally higher than those measured in vacuum, which effectively verified the existence of capillary force in the microscopic adsorption model and its influence on the adhesion effect. Through the test comparison of three groups of typical solid lubricating films, it is found that MoS ₂ has a lower adhesion effect than the other two groups of films, which can effectively reduce the adhesion phenomenon of lunar dust on the surface of the material, and provide suitable materials for future lunar exploration and manned lunar missions.