MECHANICAL-PROPERTIES OF SIC FILMS PREPARED BY DYNAMIC ION MIXING

SiC coatings have been deposited by dynamic ion mixing (DIM) at room temperature on TA6V substrates. The depositing atom Bur was obtained by sputtering a SiC target with a 1.2 keV Ar+ ion beam delivered by a Kaufman-type ion source. The coatings prepared without mixing are amorphous whereas those deposited by DIM exhibit the beginning of crystallization and their chemical analysis has revealed a relative excess of Si, The intrinsic hardness of 0.86 mu m SiC coatings was determined by application of a composite hardness model. Fully crystallized coatings obtained by thermal annealing exhibit higher hardness value whereas their adhesion performance is worse than partially amorphous coatings prepared by DIM. The wear and friction of TA6V are always improved by SIC coatings. In addition to the influence of the mixing effect, this study has demonstrated the importance of the structural state of the coating since SiC crystallized surfaces respond Very differently from the amorphous surfaces, as previously observed for bulk SiC.