Structural design and ablation performance of ZrB₂/MoSi₂ laminated coating for SiC coated carbon/carbon composites

A protective coating alternated with ZrB₂ and MoSi₂ laminated layers was designed and prepared on carbon/carbon (C/C) composites with SiC inner layer by supersonic atmosphere plasma spraying. After ablated at a heat flux of 2.4 MW/m² for 30s, ZrB₂/MoSi₂ laminated coating was in good condition with a linear growth rate and mass gain rate of 1.67 μm/s and 0.44 mg/s, respectively. From the central region to the border region, the calculated residual thermal stress of ZrB₂/MoSi₂ laminated coating decreased at first and then increased rapidly, illustrating the size change of the generated laminated cracks. The alternate design of ZrB₂ layers for erosion and MoSi₂ layers for oxidation resulted in the laminated stress distribution and improved ablation resistance.