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

摘要

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/m(2) for 30s, ZrB2/MoSi2 laminated coating was in good condition with a linear growth rate and mass gain rate of 1.67 mu m/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.