Characterization of microstructure and mechanical behavior of sputter deposited Ti-containing amorphous carbon coatings
Document Type
Article
Publication Date
12-3-2001
Abstract
We report on the characterization of microstructure and mechanical properties of sputter deposited Ti-containing amorphous carbon (Ti-aC) coatings as a function of Ti composition. Ti-aC coatings have been deposited by unbalanced magnetron sputter deposition, in an industrial-scale four-target coating deposition system. The composition and microstructure of the Ti-aC coatings have been characterized in detail by combining the techniques of Rutherford backscattering spectrometry (RBS) and hydrogen elastic recoil detection (ERD), transmission electron microscopy (TEM), X-ray absorption near edge structure (XANES) spectroscopy and extended X-ray absorption fine structure (EXAFS) spectroscopy. At Ti compositions <4at.%, Ti atoms dissolve in an amorphous carbon (a-C) matrix. The dissolution limit of Ti atoms in an a-C matrix is determined to be between 4 and 8 at.%. At Ti compositions > 8 at.%, XANES and EXAFS data indicate that the average Ti atomic bonding environment in Ti-aC coatings resembles that in cubic B1-TiC, consistent with TEM observation of precipitation of TiC nanocrystallites in the a-C matrix. Beyond the Ti dissolution limit, the Ti-aC coatings are nanocomposites with nanocrystalline TiC clusters embedded in an a-C matrix. A large scale, quasi one-dimensional composition modulation in the Ti-aC coatings was observed due to the particular coating deposition geometry. Elastic stiffness and hardness of the Ti-aC coatings were measured by instrumented nanoindentation and found to vary systematically as a function of Ti composition. Unlubricated friction coefficient of Ti-aC coatings against WC-Co balls was found to increase as the Ti composition increases. As Ti composition increases, the overall mechanical behavior of the Ti-aC coatings becomes more TiC-like. © 2001 Elsevier Science B.V. All rights reserved.
Publication Source (Journal or Book title)
Surface and Coatings Technology
First Page
153
Last Page
162
Recommended Citation
Feng, B., Cao, D., Meng, W., Xu, J., Tittsworth, R., Rehn, L., Baldo, P., & Doll, G. (2001). Characterization of microstructure and mechanical behavior of sputter deposited Ti-containing amorphous carbon coatings. Surface and Coatings Technology, 148 (2-3), 153-162. https://doi.org/10.1016/S0257-8972(01)01380-9