MECHANICAL-PROPERTIES OF SIC FILMS PREPARED BY DYNAMIC ION MIXING

SiC coatings have been deposited by dynamic ion mixing (DIM) at room t emperature 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 Ka ufman-type ion source. The coatings prepared without mixing are amorph ous whereas those deposited by DIM exhibit the beginning of crystalliz ation and their chemical analysis has revealed a relative excess of Si , The intrinsic hardness of 0.86 mu m SiC coatings was determined by a pplication of a composite hardness model. Fully crystallized coatings obtained by thermal annealing exhibit higher hardness value whereas th eir adhesion performance is worse than partially amorphous coatings pr epared by DIM. The wear and friction of TA6V are always improved by SI C coatings. In addition to the influence of the mixing effect, this st udy has demonstrated the importance of the structural state of the coa ting since SiC crystallized surfaces respond Very differently from the amorphous surfaces, as previously observed for bulk SiC.