PREPARATION OF SiC/ C FILM AND ITS MECHANICAL PROPERTIES

High-quality SiC/ C composite films were deposited with SiC ultrafine powder as a raw material by thermalplasma physical vapor deposition ( PVD) technique. The maximum deposition rate reached 225 nm/ s. The films werecharacterized with high resolution transmission electron microscope ( HRTEM) , scanning electron microscope ( SEM)and X-ray photoelectron spectrocope (XPS) . The mechanical properties of the deposited films were evaluated with ananoindenter in comparison with that of sintered SiC. The results show that when CH₄ is introduced into plasma , the deposition rate and C content of SiC/ C composite film increase , and films with columnar structure are formed. The hardnessand elastic modulus of the deposited films decrease with increasing C content in the SiC/ C composite films. The hardnessevaluated with a nanoindenter at contact depth of 40 nm reaches 38 GPa , which suggests good quality of the depositedfilms.