Morphological and mechanical studies of Al 2 O 3 -Na 2 SiO 3 as a skin barrier coated with TiO 2 for carbon fiber reinforced composite materials.

The utilization of adhesive compounds in bonding lightweight and high-performance composite structures, including carbon fiber reinforced polymer (CFRP) composites, has garnered significant attention from researchers. This study presents the novel application of Al2 O3 coated with TiO2 as a thermal protective layer for CFRP substrate. Initially, the CFRP substrate underwent a protective treatment involving the application of Al2 O3 as a middle coat, followed by a further protective layer consisting of TiO2 as a top coat. The deposition of TiO2 onto an Al2 O3 -based thermal barrier coating (TBC) was carried out utilizing the flame spray method. The use of a TiO2 coating as a top coat was employed to enhance protection and heat dispersion across the middle coat and substrate. In order to achieve sufficient adhesion between the CFRP substrate, an intermediate coat consisting of Al2 O3 with a Na2 SiO3 binder, the impact of varying nozzle distances on adhesion strength and pull-off test outcomes was investigated, with a nozzle distance of 180 mm yielding the highest adhesion strength. The thermal stability of a CFRP substrate was enhanced through the deposition of a layer of TiO2 on Al2 O3 . The surface and cross-sectional morphologies of the composite were analyzed using a Scanning Electron Microscope (SEM). It was observed that the presence of a TBC on the composite surface effectively reduced the amount of heat that was transferred to the composite material. In order to assess the effectiveness of TBC on CFRP substrates, a series of experiments involving thermal torch and conductivity tests were undertaken. The interaction between the top and middle coats of a composite material results in enhanced mechanical properties, hence improving its thermal insulation capabilities. The artificially produced TBC coatings have the potential to function as adhesive materials, ensuring the sustained high performance of CFRP substrates.