Intrinsic stresses and mechanical properties of Ti-containing hydrocarbon coatings

Abstract

A detailed examination of the intrinsic stress development within and mechanical properties of Ti containing hydrocarbon (Ti–C:H) coatings deposited in an inductively coupled plasma assisted hybrid chemical vapor deposition/physical vapor deposition environment has been carried out, combining in situ substrate curvature measurements with plasma probe measurements, ex situ electrical resistivity measurements, and instrumented nanoindentation measurements. Intrinsic stresses within Ti–C:H have been found to be compressive over wide ranging compositions and plasma parameters. The intrinsic compression within Ti–C:H was found to depend significantly on the Ti composition, and was related to a percolation type transition in the nanoscale structure. The intrinsic compression within Ti–C:H has further been shown to be significantly influenced by the energy of ionic species bombarding the substrate during growth. Measured stress–thickness history was discussed in terms of possible mechanisms contributing to intrinsic stress generation. Although there are likely multiple mechanisms influencing intrinsic stress development, our present results suggest that ion bombardment plays a significant role in intrinsic stress generation within Ti–C:H, and is likely to influence stress development in other low temperature deposited amorphous hydrocarbon based ceramic nanocomposite coatings.