@misc{ObrosovGulyaevZaketal., author = {Obrosov, Aleksei and Gulyaev, Roman and Zak, Andrzej and Ratzke, Markus and Naveed, Muhammad and Dudzinski, Wlodzimierz and Weiß, Sabine}, title = {Chemical and Morphological Characterization of Magnetron Sputtered at Different Bias Voltages Cr-Al-C Coatings}, series = {Materials}, volume = {10}, journal = {Materials}, number = {2}, issn = {1996-1944}, doi = {10.3390/ma10020156}, pages = {156}, abstract = {MAX phases (M = transition metal, A = A-group element, and X = C/N) are of special interest because they possess a unique combination of the advantages of both metals and ceramics. Most attention is attracted to the ternary carbide Cr2AlC because of its excellent high-temperature oxidation, as well as hot corrosion resistance. Despite lots of publications, up to now the influence of bias voltage on the chemical bonding structure, surface morphology, and mechanical properties of the film is still not well understood. In the current study, Cr-Al-C films were deposited on silicon wafers (100) and Inconel 718 super alloy by dc magnetron sputtering with different substrate bias voltages and investigated using Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), and nanoindentation. Transmission Electron Microscopy (TEM) was used to analyze the correlation between the growth of the films and the coating microstructure. The XPS results confirm the presence of Cr2AlC MAX phase due to a negative shift of 0.6-0.9 eV of the Al2p to pure aluminum carbide peak. The XRD results reveal the presence of Cr2AlC MAX Phase and carbide phases, as well as intermetallic AlCr2. The film thickness decreases from 8.95 to 6.98 µm with increasing bias voltage. The coatings deposited at 90 V exhibit the lowest roughness (33 nm) and granular size (76 nm) combined with the highest hardness (15.9 GPa). The ratio of Al carbide to carbide-like carbon state changes from 0.12 to 0.22 and correlates with the mechanical properties of the coatings. TEM confirms the columnar structure, with a nanocrystalline substructure, of the films.}, language = {en} } @misc{ObrosovGulyaevRatzkeetal., author = {Obrosov, Aleksei and Gulyaev, Roman and Ratzke, Markus and Volinsky, Alex A. and Bolz, Sebastian and Naveed, Muhammad and Weiß, Sabine}, title = {XPS and AFM Investigations of Ti-Al-N Coatings Fabricated Using DC Magnetron Sputtering at Various Nitrogen Flow Rates and Deposition Temperatures}, series = {Metals}, volume = {7}, journal = {Metals}, number = {2}, issn = {2075-4701}, doi = {10.3390/met7020052}, pages = {52}, abstract = {Ti-Al-N coatings were deposited by direct current magnetron sputtering (DCMS) onto IN 718 at different nitrogen flow rates and deposition temperatures. The coatings' properties were characterized using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) as well as nanoindentation. It was found that higher deposition temperature leads to higher surface roughness and nitrogen flux influences the shape of grains. According to XPS, the bonding structure of all coatings exhibited the (Ti,Al)N phase. Mechanical properties depend on the Al content within the films. The coating with the best mechanical properties (deposited at 500 °C and 20 standard cubic centimeters per minute (sccm)) was further deposited onto tungsten carbide (WC) cutting tools for cylindrical turning experiments. A quasi-constant flank wear was observed until a machining volume of 23,500 mm³.}, language = {en} }