b'Figure 4. High-angle annular dark- industrial coating vendors, Cr, CrN,of oxidation resistance) of thefield imaging (HAADF) scanningZr, and CrCxNy coatings 5-10mDCMS coating was greater than transmission electron microscopyin thickness were deposited usingHiPIMS during the initial stages (STEM) images at the surface of the (a) DCMS Cr and (b) HiPIMS Cr coatingsdirect current magnetron sputteringof oxidation due to the higher after the 30-day corrosion test; (c)(DCMS), high-power impulsesurface roughness and presence of HAADF STEM image below the surfacemagnetron sputtering (HiPIMS),nanoscale intercolumnar porosity of the DCMS coating showing theand cathodic arc processes. Amongwithin the DCMS microstructure.location of EDS line scan across an intercolumnar boundary; (d) EDS linethese coating materials, pure CrIn the next generation of coating scan data showing formation of Cr2O3coatings produced with magnetron along the intercolumnar boundary sputtering demonstrated the bestdevelopment, the investigation of mechanical properties as determinedsputter deposition technologies by micro- and nano-mechanicalwas expanded to include processes testing and scratch tests. which incorporate secondary ion bombardment and target voltage As an initial evaluation of thepulsing. Extensive microstructural protective capability of the coating,characterization using transmission SiC samples coated with DCMSelectron microscopy was conducted Cr and HiPIMS Cr were subjectedto understand the influence of to a 30-day static water corrosionthese deposition parameters on test at 360 C at the University ofgrain size, morphology, and density. Wisconsin. It was found that bothIon-assisted DCMS was found types of Cr coatings preventedto enhance densification of the hydrothermal corrosion of themicrostructure through atomic underlying SiC through the forma- peening effects, while pulsed tion of a passive Cr2O3 layer 20-30DCMS promoted columnar grain nm thick on the coating surface. growth. A state-of-the-art bipolar The weight gain (an inverse measureHiPIMS (B-HiPIMS) process was 76 2022|AFC ACCOMPLISHMENTS'