Effet de plasmas des ions d'argon(Ar+) sur l'interaction entre des couches minces réfractaires et des substrats en acier : analyse par le rayonnement x

Abstract

Hard protectlve coatings have significantry improved the performance of the surfaces of tools exposed to frictlon and withwear-aNewcombinationdeveropments'of advantageousaim at producingmaterialprotectivepropertiescoatingssuch as enhanced hardness or v/ear resistance. TiEanlum carbides aç"e"È_ones of the most used. In this work h/e study the influence of plasmas conditions in pVD method on the obtained coatings properties. !{e have prepare Tw.o series of samples ' Thin titanium films are deposited on steel substrates f1lms100c6andof substrates.1% carbon. TheTo activatesamples arethesustainedreacti_onheatbetweentreatmentthin under vacuum in the temperature range 2oo to 1000 " c. The difsamplesf ractionand(XRD)substrates, scanninghTereel_ectroncharacterizedmicroscopewith(SEM)x-râyr X microanalysis (EDs) and Auger el-ectron spectroscopy. High pressures of argon ions and high kinetic ...rgy of atoms removed from the target provide coatings with open structures, less hard and easy to oxidize. The xRD spectra and concentration profiles by AES show these observations in the samples of both series. The morphological study of the first serj_es sampres shows an open structure and severar kinds of cracking and 1n others a total detachment of the thin film, especially in the high temperature annealing. However, the structure of sampres of series 2 is compact and hornogeneous. The measurements of microhardness with Vikers method gives important values for samples of series 2, reaches a maximum and then begins to decrease. The i-ncrease of Hv is due to the dif f usi-on of carbon f rom substrate to titanium film and the formation of titanium carbides. The decrease of Hv is due to the diffusion of oxygen and iron to the external layers and the formation of the oxides TiOz, FezOr.