Low-pressure plasma spraying of ZrB2-SiC coatings on C/C substrate by adding TaSi2

Abstract

To improve the density and ablation resistance of ZrB 2 -SiC coatings, TaSi 2 modified ZrB 2 -SiC coatings was prepared on C/C composites by low-pressure plasma spraying . Systematical investigations about microstructures of two kinds of ceramic coatings were performed by XRD, SEM, EDS , TEM and X-ray computed tomography . The presence of Ta element in the ZrB 2 -SiC-TaSi 2 coating is mainly in the form of fine particles with nanoscale , (Zr 0.8 Ta 0.2 )B 2 , visible fine particles and densification areas. The addition of TaSi 2 is conducive to reducing the porosity of the coatings and improving their mechanical and ablation resistance properties. • The IPS and low-pressure plasma spraying technology were both introduced to prepare the coating layers. • Systematical investigations about microstructures of ZS and ZST coatings were performed by methods of characterization. • The TaSi 2 addition in the ZST coatings prepared by LPPS have different microstructures is firstly found and reported. • The ZrB 2 -SiC-TaSi 2 coatings prepared by IPS and low-pressure plasma spraying have lower porosity and better performance.