Tribology and Anti-Ablation Properties of SiC-VN-MoS2/Ta Composite Coatings on Carbon/Carbon Composites from 25 to 800 °C

Abstract

To improve the self-lubrication and anti-ablation performances of C/C (carbon/carbon) composites from 25 to 800 °C, we engineered three layers of composite coatings consisting of SiC–VN–MoS2/Ta to deposit on the surface of the C/C composites. The tribology and anti-ablation properties of the composite coatings were experimented under dry sliding wear. The equivalent stress and deformation of the composite coatings are studied. The results show that the CoFs (coefficients of friction) of the C/C composites are decreased by 156% at 800 °C due to the new generated self-lubricating compounds from the MoS2/Ta and VN coating. The anti-ablation of the C/C composites are improved by 25,300% due to the silicon glass, and the generated compounds from V, Mo and Si. The deformation of the C/C substrate under the protection of these coatings looks like a quadrangular star. The cack of the C/C composites is easily generated without the protection from coatings.

Microstructure-Based Thermochemical Ablation Model of Carbon/Carbon-Fiber Composites

“…Carbon fiber-reinforced carbon-matrix composites (carbon/carbon composites), which possess high latent heat of sublimation, excellent strength, and chemical stability at high temperatures, have been widely used as thermal protection materials in atmospheric re-entry vehicle heat shields and rocket engine nozzles [1][2][3][4][5][6][7][8][9][10][11]. High-temperature, highpressure, and high-velocity airflow are present in the typical service environments of carbon/carbon composites.…”

“…Numerous researchers have focused on the thermochemical ablation behavior of carbon/carbon composites under high-temperature airflow [17][18][19], especially on its analysis models. These studies can generally be divided into the study of: (1) heat transfer analysis [20][21][22], (2) detailed chemical reactions [23][24][25], (3) surface ablation morphology [26,27], and (4) the effects of the material microstructure on ablation characteristics [28][29][30]. In the aspect of heat transfer analysis, the thermal response was simulated from the perspective of the matrix and fiber components of various braided carbon/carbon composites [31,32].…”