The titanium alloy, Ti-6%Al-4%V, has many attractive properties including a high elastic modulus, relatively low density, and high specific strength. Such properties have resulted in its widespread use in the aerospace and biomedical industry. It is projected that enhancing the wear resistance of these alloys could further extend their engineering applications. It has been reported that substantial improvements in tribological performance can be realized through deposition of a thin diamond coating. However, the adhesion characteristics of such coatings on Ti-6%Al-4%V alloys are poor. This is primarily due to differences in thermal expansion coefficients between the diamond and titanium alloy which generates high stresses at the coating/substrate interface.

The oxy-acetylene combustion flame technique was employed to assist in the development of adherent diamond coatings on Ti-6%Al-4%V alloy. The effect of fundamental process parameters such as substrate temperature, inlet gas stoichiometry, and substrate position in the flame on nucleation and growth rate, morphology, and coating adhesion were quantitatively and qualitatively evaluated. Process parameters were optimized to yield high quality, continuous diamond coatings on the titanium alloy substrates. The coatings were characterized using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The adhesion was evaluated by indentation and macroscratching testing techniques.

The mechanical properties of CVD diamond films must be known as quantitatively as possible in order to render them to be usable for various industrial parts. In regard of this several investigators have measured the properties in question, but their results including, for example, those on Young's modulus and fracture strength have been inadequate particularly from the view point of clarifying the effect of the thickness and test temperature.

In this paper, the above-mentioned properties to be the most fundamental mechanical ones were evaluated. Three points bendig test conducted under R.T.-1073K have been employed for investigating the relationship between stress - strain curves and thickness of free standing diamond films. The effects of film thickness and test temperature on Young's modulus and fracture strength of the films were discussed on the basis of these experimental results.

Silicon carbide is a wide band gap semiconducter, which also has excellent mechanical properties. It can be used as a hard coating even in aggressive environs and at high temperatures due to its excellent chemical stability.

Silicon carbide films of a thickness of up to one micron have been formed on silicon and silicon on sapphire substrates by evaporating fullerene (C60) molecules onto the heated targets. The influence of UV light irradiation during the carbonization has also been studied. The stoichiometry of the layers has been examined with Rutherford backscattering spectrometry. The results show, that it is possible to form stoichiometric (Si:C ratio 1:1) layers with this technique. The phase composition and microstructure of the films have been investigated by X-ray pole figure measurements and by cross sectional transmission electron microscopy. It is shown that the silicon carbide grows columnarily and mostly consists of the hexagonal phase. With this technique, silicon carbide films can be deposited onto several materials, if prior to carbonization a silicon film has been evaporated.