| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2016) | |
| Thin Films | Thursday Sessions |
| Session TF-ThM |
| Session: | Advanced Protective Coatings/Stress Evolution, Nanostructure, and Physical Properties of Thin Films |
| Presenter: | WenJin Meng, Louisiana State University, USA |
| Authors: | X. Zhang, Louisiana State University, USA Y. Mu, Louisiana State University, USA W.J. Meng, Louisiana State University, USA |
| Correspondent: | Click to Email |
Quantitative evaluation of critical stresses governing interfacial failures in coating/substrate systems is crucial for surface engineering via the application of coatings to substrates. While a number of measurement techniques have been developed and studied over the past two decades, quantitative measurement of critical stresses leading to interfacial failures in coating/substrate systems has remained a challenge.
We report a new micro pillar compression testing protocol for quantitative measurement of interfacial shear failure stress in ceramic coating/metal adhesion layer/substrate systems. Three specimen series were investigated: CrN/Cu/Si, CrN/Ti/Si, and CrN/Cr/Si. All film/coating depositions occurred in a UHV plasma assisted magnetron sputtering system. Specimen characterization was accomplished through X-ray diffraction (XRD), focused ion beam and scanning electron microscope(FIB/SEM), and transmitted electron microscope (TEM). Scripted FIB cutting was used to fabricate cylindrical micro-pillars of the three specimen series, with interfaces inclined at 45deg with respect to the pillar axes. Compression loading of micro-pillars was carried out on an instrumented nano-indentation device. Depending on the interfacial adhesion layer used, the testing results show clear differences in the critical shear failure stress. The present results show the efficacy of this new microscale testing protocol, and motivate further study of the mechanical integrity of coating/substrate interfaces.