LAUSR

Abstract PSN/borosilicate glass-B4C coating was designed for use as field-based repair coating on carbon/carbon (C/C) composites for aircraft brakes. The first PSN layer was transition layer that improved wettability between glass coating and C/C, and the second layer of borosilicate glass-B4C formed outer glass layer. Effect of B4C content on oxidation behavior of C/C repair coating was investigated. The coating with 25 wt% B4C demonstrated excellent oxidation resistance and could effectively protect C/C composites from oxidation. Weight losses of −3.1% at 700 °C and −2.9% at 900 °C were observed after being oxidized for 10 h. Repair coating with smooth, dense, and crack-free structure could be rapidly formed as B4C content of the coating increased to 25 wt% and 35 wt% with increasing oxidation time. B4C in repair coating could be oxidized into B2O3 glass and it could heal defects in the coating. Residual B4C dispersed in the coating could dispersion strengthen glass coating and inhibit crack formation in the coating.