Depositing CNTs on the interface and surface of C/PyC/SiCs for tunable mechanical and electromagnetic properties

The incorporation of carbon nanotubes (CNTs) in carbon fiber reinforced silicon carbide composites with pyrolytic carbon interface (C/PyC/SiCs) can be very beneficial for aerospace and military applications. In the present study, CNTs were introduced onto internal PyC interface (I-CNTs) and onto external SiC surface (C-CNTs) through electrophoretic deposition (EPD) method to tune the mechanical and electromagnetic properties of C/PyC/SiCs. Results indicated that with the increase of EPD duration, flexural strength of I-CNTs and C-CNTs increased by 25.3% and 11.4%, respectively, owing to energy consumption of CNTs between PyC interface and SiC matrix. The electrical conductivity of I-CNTs and C-CNTs were found to be in a quadratic relation with EPD duration, while the conductivity of I-CNTs increases from 4.21 to 5.96 S/cm and that of C-CNTs increases from 4.47 to 5.77 S/cm. The absorption and total electromagnetic shielding effectiveness of I-CNTs was found to be higher than that of C-CNTs due to the increase of CNTs content on PyC interface and electrical conductivity. Therefore, the I-CNTs with excellent mechanical and electromagnetic shielding performance can be used in various applications.