Abstract:Suspension Plasma Spraying (SPS) adopts a liquid-phase feeding method, which solves the difficulty of feeding nano-scale powders during thermal spraying. At the same time, it can deposit coatings with nano-scale or sub-micron columnar crystals or vertical cracks. This paper reviews the relevant research progress in the preparation of thermal barrier coatings by SPS in recent years. It introduces the principles and technological characteristics of SPS and expounds the deposition mechanism of typical microstructures of thermal barrier coatings prepared by SPS, including vertical cracks and columnar crystal structures. The effects of suspension characteristics (including solid content, viscosity, and surface tension), spraying process parameters (including spray gun type and spraying distance), and substrate surface roughness on the microstructure, thermophysical properties, and thermal cycling performance of SPS-deposited coatings are also discussed. Finally, the future development and research trends of SPS are projected.