CHARACTERIZATION OF THE STRENGTH AND ADHESION OF DIAMOND FILMS ON METALLIC SUBSTRATES USING A SUBSTRATE PLASTIC STRAINING TECHNIQUE

Diamond films have been deposited by microwave plasma-assisted CVD on two different metallic substrates (304 stainless steel and Ti-6Al-4V). The film thickness was also varied within the range of a few micrometres. The strength and adhesion of these coatings have been measured by a substrate plastic straining technique. The information about the distribution of the crack spacing has been utilized to estimate the Weibull moduli of the films. The data presented in this paper indicate that the films exhibit excellent adhesion to the substrates. The average strength of the films appears to be greater for lower thicknesses. The films on titanium substrates show greater strengths and a somewhat higher value of Weibull modulus.