Development of multi-step coating of ZrC on C-C composites for surface crack improvement

Vacuum Plasma Spray (VPS) is a coating process using molten powders in high temperate and high velocity plasma in vacuum condition to collide with substrates. VPS coating systems have been applied to various fields because of its many advantages. However, some cracks in parallel or perpendicular to the surface of coating layer or interface between layers are inevitable and cause the degradation in adhesive and/or thermal protective performance of coated layers. In this work, therefore, we studied the effects of a multi-step coating of ZrC on carbon-carbon (C-C) composite to reduce the surface crack generation via mitigating the interfacial stresses between ZrC and C-C layers. To evaluate physical and chemical properties of coated layers, microstructural and mechanical analyses were also performed using X-ray diffraction (XRD), scanning electron microscope (SEM) and Vickers hardness test.

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This work was supported by the Agency for Defense Development Grand Funded by the Korean Government (UE2130241D)