TY - GEN A1 - Naveed, Muhammad A1 - Obrosov, Aleksei A1 - Weiß, Sabine T1 - Investigation of the wear resistance properties of Cr/CrN multilayer coatings against sand erosion T2 - Conference Papers in Science N2 - The wear of metallic components used in gas and steam turbines due to erosive sand particles lead to a tremendous decrease in their lifetime. This wear can be reduced by the use of suitable erosion resistant coatings resulting in lower maintenance costs. In this context, multilayer Cr/CrN PVD coatings using an industrial coater was designed and applied on Inconel 718, a material which finds its application in gas turbines. A variation in the bimodal period has been induced in order to achieve an optimal coating architecture providing optimum properties needed for the erosion resistant coatings. The coating was deposited using a single Cr- target with an induction of N2 during the nitriding phase at a temperature of 480-500 °C and the coating thickness of 24-26 µm was kept constant throughout. The erosion tests were conducted at angles of 30°, 60° and 90°. The sand used for the test is an irregular shaped SiO2. The erosion tests were followed by a detailed microscopic examination of the eroded coating structure in combination with nanoindentation and scratch tests. KW - Cr/CrN multilayer, Erosion, PVD, Coatings Y1 - 2015 U6 - https://doi.org/10.1155/2015/873543 N1 - Article ID 873543 VL - 2015 SP - 1 EP - 10 ER - TY - GEN A1 - Naveed, Muhammad A1 - Obrosov, Aleksei A1 - Zak, Andrzej A1 - Dudzinski, Wlodzimierz A1 - Volinsky, Alex A. A1 - Weiß, Sabine T1 - Sputtering Power Effects on Growth and Mechanical Properties of Cr2AlC MAX Phase Coatings T2 - Metals N2 - Coating growth and mechanical properties of nanolamellar Cr2AlC coatings at various sputtering power were investigated in the present study. Cr2AlC coating was deposited on the IN 718 superalloy and (100) Si wafers by DC magnetron sputtering at different sputtering powers. The structure and properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nanoindentation. It was found that coatings had columnar structure with nanocrystalline substructure. Deposition rate increased with the sputtering power. XRD results showed the presence of the Cr2AlC MAX phase, intermetallic AlCr2 and Cr7C3 carbide phases, along with the change in preferential coating growth orientation. TEM observations confirmed the occurrence of these phases, and the SAED patterns demonstrated significant texture of the coatings. Hardness values were measured in the range between 11–14 GPa, showing a slight increase with the sputtering power. KW - MAX Phase KW - Cr2AlC KW - TEM Y1 - 2016 U6 - https://doi.org/10.3390/met6110265 SN - 2075-4701 VL - 6 IS - 11 SP - 265 ER - TY - GEN A1 - Obrosov, Aleksei A1 - Naveed, Muhammad A1 - Volinsky, Alex A. A1 - Weiß, Sabine T1 - Substrate Frequency Effects on CrxN Coatings Deposited by DC Magnetron Sputtering T2 - Journal of Materials Engineering and Performance N2 - Controlled ion bombardment is a popular method to fabricate desirable coating structures and modify their properties. Substrate biasing at high frequencies is a possible technique, which allows higher ion density at the substrate compared with DC current bias. Moreover, high ion energy along with controlled adatom mobility would lead to improved coating growth. This paper focuses on a similar type of study, where effects of coating growth and properties of DC magnetron-sputtered chromium nitride (CrxN) coatings at various substrate bias frequencies are discussed. CrxN coatings were deposited by pulsed DC magnetron sputtering on Inconel 718 and (100) silicon substrates at 110, 160 and 280 kHz frequency at low duty cycle. Coating microstructure and morphology were studied by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), scratch adhesion testing and nanoindentation. Results indicate a transformation of columnar into glassy structure of CrxN coatings with the substrate bias frequency increase. This transformation is attributed to preferential formation of the Cr2N phase at high frequencies compared with CrN at low frequencies. Increase in frequency leads to an increase in deposition rate, which is believed to be due to increase in plasma ion density and energy of the incident adatoms. An increase in coating hardness along with decrease in elastic modulus was observed at high frequencies. Scratch tests show a slight increase in coating adhesion, whereas no clear increase in coating roughness can be found with the substrate bias frequency. KW - adhesion of coatings KW - CrN coatings KW - frequency KW - mechanical properties KW - microstructure KW - PVD KW - X-ray diffraction Y1 - 2016 UR - http://link.springer.com/article/10.1007/s11665-016-2426-4 U6 - https://doi.org/10.1007/s11665-016-2426-4 SN - 1544-1024 VL - 26 IS - 1 SP - 366 EP - 373 ER - TY - GEN A1 - Obrosov, Aleksei A1 - Gulyaev, Roman A1 - Zak, Andrzej A1 - Ratzke, Markus A1 - Naveed, Muhammad A1 - Dudzinski, Wlodzimierz A1 - Weiß, Sabine T1 - Chemical and Morphological Characterization of Magnetron Sputtered at Different Bias Voltages Cr-Al-C Coatings T2 - Materials N2 - 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. KW - XPS KW - AFM KW - MAX phase KW - TEM KW - chemical bonding KW - surface morphology Y1 - 2017 UR - http://www.mdpi.com/1996-1944/10/2/156/htm U6 - https://doi.org/10.3390/ma10020156 SN - 1996-1944 VL - 10 IS - 2 SP - 156 ER - TY - GEN A1 - Obrosov, Aleksei A1 - Gulyaev, Roman A1 - Ratzke, Markus A1 - Volinsky, Alex A. A1 - Bolz, Sebastian A1 - Naveed, Muhammad A1 - Weiß, Sabine T1 - XPS and AFM Investigations of Ti-Al-N Coatings Fabricated Using DC Magnetron Sputtering at Various Nitrogen Flow Rates and Deposition Temperatures T2 - Metals N2 - 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. KW - Ti-Al-N coatings KW - DC magnetron sputtering KW - XPS KW - AFM KW - nitrogen flow rate KW - surface morphology Y1 - 2017 UR - http://www.mdpi.com/2075-4701/7/2/52/htm U6 - https://doi.org/10.3390/met7020052 SN - 2075-4701 VL - 7 IS - 2 SP - 52 ER - TY - CHAP A1 - Kashkarov, Egor B. A1 - Sutygina, Alina A1 - Nikitenkov, Nikolay A1 - Syrtanov, Maxim S. A1 - Obrosov, Aleksei ED - Tiwari, Ashutosh T1 - Microstructure changes and hydrogenation behaviour of Zr-1Nb alloy after plasma immersion titanium implantation at different time of exposure T2 - American Advanced Materials Congress 2016 N2 - Zirconium alloys are the main construction materials of water-cooled nuclear reactors. Zirconium is used in the core of nuclear reactors as fuel element claddings due to low thermal-neutron capture cross section. Hydrogen is released in the process of water radiolysis or high-temperature oxidation of fuel claddings under loss of coolant accident (LOCA) conditions. The penetration and accumulation of hydrogen in zirconium alloys lead to degradation of their physical and mechanical properties caused by hydrogen embrittlement and delayed hydride cracking [1, 2]. Plasma immersion ion implantation (PIII) is widely used to improve the mechanical properties, corrosion and erosion resistance as well as to decrease hydrogen absorption rate of zirconium [3, 4]. During PIII, a plasma ions are accelerated by high voltage pulsed bias applied to the target. The accelerated ions penetrate in the bulk of the target and modify the deeper layers of materials. Previous studies shown that PIII of titanium improves the protection properties of Zr-2.5Nb alloy from hydrogenation [5]. Moreover, the microdroplets and ion energy have significant impact on hydrogen absorption of the alloys. However, it is necessary to understand the mechanism of hydrogen interaction with the modified layers depending on the time of implantation. In this study, titanium ions were implanted into Zr-1Nb alloy target using filtered vacuum arc source and high frequency short pulser. Coaxial plasma filter was used to reduce the number and size of microdroplets evaporated from the cathode spots. The implantation parameters are: 70 A arc current, 0.15 Pa argon pressure, 1500 V pulsed bias, 100 kHz repetition frequency, 5 μs pulse length and 5-30 min implantation time. Gas-phase hydrogenation was performed at 623 K and 2 atm. hydrogen pressure for 60 min. Surface morphology, phase composition and depth distribution of elements were investigated using scanning electron and atomic force microscopies (SEM and AFM), X-ray diffraction and glow-discharge optical emission spectroscopy (GDOES). It was revealed that the microdroplets and craters with the size of several microns are formed after titanium implantation. The number and size of craters are increased with implantation time from 5 to 30 minutes. It is assumed that the presence of craters on the surface caused by bombardment of an accelerated ion clusters, which is formed due to incorporation (condensation) and ionization of evaporated atoms near the cathode region. Furthermore, the surface becomes rougher and the microstructure changes to fine-grained with an average grain size of 50-100 nm with increase of implantation time. Hydrogenation behaviour depends on the implantation time and differs from the non-treated Zr-1Nb alloy. Hydrogen absorption rate decreases by two times with increase in implantation time from 5 to 30 min. Furthermore, hydrogen preferably accumulates in the modified layer at higher implantation time. The distribution of hydrogen tends to decrease in the depth of implanted layer. The phase state of the alloy has not changed after implantation, however, the extensive distortions of the crystal lattice are observed after hydrogenation of the non-treated and implanted for 5 min Zr-1Nb alloys. KW - implantation KW - titanium KW - zirconium KW - hydrogenation KW - microstructure Y1 - 2016 SN - 978-91-88252-03-6 PB - VBRI Press CY - Linköping ER - TY - GEN A1 - Obrosov, Aleksei A1 - Sutygina, Alina A1 - Volinsky, Alex A. A1 - Manakhov, Anton A1 - Weiß, Sabine A1 - Kashkarov, Egor B. T1 - Effect of Hydrogen Exposure on Mechanical and Tribological Behavior of CrₓN Coatings Deposited at Different Pressures on IN718 T2 - Materials N2 - In the current study, the properties of the CrₓN coatings deposited on the Inconel 718 superalloy using direct current reactive magnetron sputtering are investigated. The influence of working pressure on the microstructure, mechanical, and tribological properties of the CrₓN coatings before and after high-temperature hydrogen exposure is studied. The cross-sectional scanning electron micrographs indicate the columnar structure of the coatings, which changes from dense and compact columns to large columns with increasing working pressure. The Cr/N ratio increases from 1.4 to 1.9 with increasing working pressure from 300 to 900 mPa, respectively. X-ray diffraction analysis reveals a change from mixed hcp-Cr₂N and fcc-CrN structure to approximately stoichiometric Cr₂N phase. After gas-phase hydrogenation, the coating deposited at 300 mPa exhibits the lowest hydrogen absorption at 600 °C of all investigated coatings. The results indicate that the dense mixed cubic and hexagonal structure is preferential for hydrogen permeation resistance due to the presence of cubic phase with higher packing density in comparison to the hexagonal structure. After hydrogenation, no changes in phase composition were observed; however, a small amount of hydrogen is accumulated in the coatings. An increase of coating hardness and elastic modulus was observed after hydrogen exposure. Tribological tests reveal that hydrogenation leads to a decrease of the friction coefficient up to 20%–30%. The best value of 0.25 was reached for hydrogen exposed CrₓN coating deposited at 300 mPa. KW - CrₓN coatings KW - PVD KW - hydrogenation KW - tribology KW - mechanical properties KW - GDOES Y1 - 2017 UR - http://www.mdpi.com/1996-1944/10/5/563/htm U6 - https://doi.org/10.3390/ma10050563 SN - 1996-1944 VL - 10 IS - 5 SP - 563 ER - TY - CHAP A1 - Obrosov, Aleksei A1 - Kashkarov, Egor B. A1 - Weiß, Sabine A1 - Volinsky, Alex A. ED - Tiwari, Ashutosh T1 - Mechanical and tribological behaviour of hydrogenated CrxN coatings deposited at different pressure and voltages on IN718 T2 - American Advanced Materials Congress 2016 N2 - Hydrogen degradation is a serious problem in industrial applications like power plants (boilers, turbines), marine structures, car and aircraft components, as it leads to failures as well as to deterioration of properties. Inconel 718 is one of the most commonly used materials for these applications. Different metal nitrides like TiN coatings have been deposited in past to prevent hydrogen degradation, which are also known for their high hardness and good wear resistance [1, 2]. However, reports on hydrogen degradation of CrN coatings, which shows better oxidation and corrosion resistance, higher temperature stability and lower friction coefficient than TiN [3, 4] has not been reported till now. Despite a lot of publications about CrN films, up to now the effect of hydrogenation on mechanical and tribological properties of CrN coatings is still not completely understood. In the current work CrxN coatings were deposited by Direct Current Magnetron Sputtering (dcMS) on Inconel 718 substrate at different chamber pressures and substrate voltages. Substrate voltage is one of the most important process parameters which determines the structure of the coating and the adhesion between substrate and coating. Simultaneously a study of the chamber pressure is also needed to understand the deposited structure and growth rate because at higher pressures the high number of argon atoms reduce the number of ionized ions available for the deposition leading to low deposition rates [5]. Gas-phase hydrogenation of the samples was performed at a temperature of 600° C and hydrogen pressure of 2 atm. It was found that CrxN coatings are resistant against hydrogen exposure as compared to uncoated surfaces. The results of changes in the mechanical, tribological properties and phase composition of the coatings after hydrogenation are discussed. Coating microstructure was studied by scanning electron microscopy (SEM). The mechanical properties of the coatings were characterized by means of nanoindentation and scratch test. KW - CrxN coating KW - mechanical properties KW - microstructure KW - hydrogenation KW - XRD Y1 - 2016 SN - 978-91-88252-03-6 PB - VBRI Press CY - Linköping ER - TY - GEN A1 - Obrosov, Aleksei A1 - Naveed, Muhammad A1 - Krupp, Ulrich A1 - Solovev, Mikhail A1 - Weiß, Sabine T1 - Investigation of TiAlN HiPIMS coating deposited on the newly developed Ni-based superalloy AD730 N2 - The development of new alloys for gas turbine engines has been focused on withstanding against increasing service temperatures. AD730™ is a recently developed nickel-based superalloy for turbine disk applications with superior properties at 700°C, which is higher than the common service temperature for IN718. Use of coatings to enhance the properties of materials, such as wear resistance is widely known in various applications. This research presents an experimental study of TiAlN coatings, deposited onto AD730 superalloy using High Power Impulse Magnetron Sputtering (HiPIMS). Phase structure and chemical composition of the TiAlN films were characterized by X-ray diffractometry. Transmission electron microscopy as well as scanning electron microscopy were used to analyze the microstructure of the coating. Mechanical properties, including hardness, Young's modulus, and adhesion strength were measured using nanoindentation und scratch test. KW - TiAlN coating KW - HiPIMS KW - Ni-based superalloy KW - AD730 TEM XRD Y1 - 2016 UR - http://www.pse-conferences.net/poster-wednesday.html UR - http://www.pse-conferences.net/tl_files/abstract-print/PSE2016-PO3023.pdf N1 - 16th International Conference on Plasma Surface Engineering ER - TY - GEN A1 - Obrosov, Aleksei A1 - Naveed, Muhammad A1 - Weiß, Sabine T1 - Effect of pulse time on structure and mechanical properties of HPPMS deposited AlTiN coatings N2 - The use of PVD AlTiN as a protective coating on cutting tools is well known. With the introduction of pulsed deposition techniques like High Power Pulsed Sputtering (HPPMS), a possibility is provided to the coating developers to design their coatings by the variation in pulse parameters. To analyze the effect of pulse time HPPMS AlTiN coatings were deposited on Si (100) as well as 100Cr6 steel plates at a temperature of 500°C in a reactive gas environment. Oscilloscope measurements depicted a change in current-voltage characteristics with variation in pulse time. This influence the coating structure, deposition rates and phase formations as well. Nanoindentation results show a variation in the mechanical properties of the coatings with the change in pulse time. This study focuses on the potential of HPPMS technology for enhancement of mechanical and structural properties of AlTiN coating. KW - HPPMS KW - AlTiN KW - wear KW - cutting tools KW - pulse time Y1 - 2016 UR - http://www.pse-conferences.net/poster-wednesday.html UR - http://www.pse-conferences.net/tl_files/abstract-print/PSE2016-PO3055.pdf N1 - 16th International Conference on Plasma Surface Engineering ER - TY - GEN A1 - Kashkarov, Egor B. A1 - Nikitenkov, Nikolay A1 - Sutygina, Alina A1 - Laptev, Roman A1 - Bordulev, Yuriy A1 - Obrosov, Aleksei A1 - Liedke, Maciej O. A1 - Zak, Andrzej A1 - Weiß, Sabine T1 - Microstructure, defect structure and hydrogen trapping in zirconium alloy Zr-1Nb treated by plasma immersion Ti ion implantation and deposition T2 - Journal of Alloys and Compounds N2 - The effect of low energy plasma immersion ion implantation and deposition of titanium on microstructure, defect structure and hydrogen trapping in zirconium alloy Zr-1Nb was studied. Defect structure and distribution were analyzed by Doppler broadening using slow positron beam. The surface microstructure after modification is represented by nanostructured Ti grains with random orientation. The gradient distribution of titanium as well as vacancy type defects were analyzed. The concentration of vacancy type defects is rising with increasing bias voltage. Gas-phase hydrogenation of the Ti-modified Zr-1Nb alloy was performed at 400 °C for 60 min. The strong interaction of hydrogen with vacancy type defects was demonstrated. Two different changes in the defect structure after hydrogenation were observed: when a titanium film is formed on the surface (after deposition at 500 V) hydrogen trapping occurs with the formation of titanium hydride phases, while in the implanted layer (deposition at 1000 and 1500 V) hydrogen is trapped due to interaction with vacancy type defects. The physical basis of Ti diffusion and its influence on the evolution of defect structure after surface modification and hydrogenation were discussed. KW - Zirconium KW - Ion implantation KW - Titanium KW - Diffusion KW - Surface modification KW - Hydrogen trapping KW - Microstructure KW - Slow positrons KW - Doppler broadening KW - Defects Y1 - 2018 UR - http://www.sciencedirect.com/science/article/pii/S0925838817335879 U6 - https://doi.org/10.1016/j.jallcom.2017.10.151 SN - 0925-8388 VL - 732 SP - 80 EP - 87 ER - TY - GEN A1 - Shulepov, Ivan A. A1 - Kashkarov, Egor B. A1 - Stepanov, Igor B. A1 - Syrtanov, Maxim S. A1 - Sutygina, Alina A1 - Shanenkov, Ivan A1 - Obrosov, Aleksei A1 - Weiß, Sabine T1 - The Formation of Composite Ti-Al-N Coatings Using Filtered Vacuum Arc Deposition with Separate Cathodes T2 - Metals N2 - Ti-Al-N coatings were deposited on high-speed steel substrates by filtered vacuum arc deposition (FVAD) during evaporation of aluminum and titanium cathodes. Distribution of elements, phase composition, and mechanical properties of Ti-Al-N coatings were investigated using Auger electron spectroscopy (AES), X-ray diffraction (XRD), transmission electron microscopy (TEM) and nanoindentation, respectively. Additionally, tribological tests and scratch tests of the coatings were performed. The stoichiometry of the coating changes from Ti0.6Al0.4N to Ti0.48Al0.52N with increasing aluminum arc current from 70 A to 90 A, respectively. XRD and TEM showed only face-centered cubic Ti-Al-N phase with preferred orientation of the crystallites in (220) direction with respect to the sample normal and without precipitates of AlN or intermetallics inside the coatings. Incorporation of Al into the TiN lattice caused shifting of the (220) reflex to a higher 2θ angle with increasing Al content. Low content and size of microdroplets were obtained using coaxial plasma filters, which provides good mechanical and tribological properties of the coatings. The highest value of microhardness (36 GPa) and the best wear-resistance were achieved for the coating with higher Al content, thus for Ti0.48Al0.52N. These coatings exhibit good adhesive properties up to 30 N load in the scratch tests. KW - filtered vacuum arc KW - deposition KW - TiAlN KW - separate cathodes KW - phase composition KW - hardness KW - wear-resistance Y1 - 2017 UR - http://www.mdpi.com/2075-4701/7/11/497/htm U6 - https://doi.org/10.3390/met7110497 SN - 2075-4701 VL - 7 IS - 11 ER - TY - GEN A1 - Obrosov, Aleksei A1 - Sutygina, Alina A1 - Manakhov, Anton A1 - Bolz, Sebastian A1 - Weiß, Sabine A1 - Kashkarov, Egor B. T1 - Oxidation Behavior of Zr–1Nb Corroded in Air at 400 °C after Plasma Immersion Titanium Implantation T2 - Metals N2 - In this paper, the influence of plasma immersion titanium implantation into the zirconium alloy Zr-1Nb on the oxidation behavior at 400 °C for 5, 24, 72, and 240 h in air under normal atmospheric pressure (101.3 kPa) was shown. The influence of implantation on the protective properties of the modified layer was shown. The valence of the oxides before and after implantation was analyzed by means of X-ray photoelectron spectroscopy (XPS). Grazing incidence X-ray diffraction (GIXRD) was carried out to examine the phase composition after titanium ion implantation and oxidation. Differential scanning calorimetry (DSC) revealed that titanium implantation exhibited effects of stabilizing the β phase. The formation of the t-ZrO2 and m-ZrO2 was observed during the oxidation of the as-received and modified Zr-1Nb. The measurement of weight gain showed an improvement in oxidation resistance of Ti implanted Zr-1Nb at the oxidation up to 24 h when compared with that of the as-received Zr-1Nb. However, at longer oxidation cycle the oxidation rate of Ti-implanted zirconium alloy is the same with the as-received alloy, which attributed to the layer thickness. Nevertheless, the corrosion of the Ti-implanted alloy is more uniform, while a local corrosion and cracks was detected on the surface of the as-received alloy. KW - zirconium alloy KW - titanium KW - ion implantation KW - PIII KW - oxidation KW - DSC KW - XPS KW - surface morphology KW - X-ray diffraction Y1 - 2018 UR - http://www.mdpi.com/2075-4701/8/1/27/htm U6 - https://doi.org/10.3390/met8010027 SN - 2075-4701 VL - 8 IS - 1 ER - TY - GEN A1 - Solovieva, Anastasiya A1 - Miroshnichenko, Svetlana A1 - Kovalskii, Andrey A1 - Permyakova, Elizaveta A1 - Popov, Zakhar A1 - Dvořáková, Eva A1 - Kiryukhantsev-Korneev, Philip A1 - Obrosov, Aleksei A1 - Polčak, Josef A1 - Zajíčková, Lenka A1 - Shtansky, Dmitry V. A1 - Manakhov, Anton T1 - Immobilization of Platelet-Rich Plasma onto COOH Plasma-Coated PCL Nanofibers Boost Viability and Proliferation of Human Mesenchymal Stem Cells T2 - Polymers N2 - The scaffolds made of polycaprolactone (PCL) are actively employed in different areas of biology and medicine, especially in tissue engineering. However, the usage of unmodified PCL is significantly restricted by the hydrophobicity of its surface, due to the fact that its inert surface hinders the adhesion of cells and the cell interactions on PCL surface. In this work, the surface of PCL nanofibers is modified by Ar/CO2/C2H4 plasma depositing active COOH groups in the amount of 0.57 at % that were later used for the immobilization of platelet-rich plasma (PRP). The modification of PCL nanofibers significantly enhances the viability and proliferation (by hundred times) of human mesenchymal stem cells, and decreases apoptotic cell death to a normal level. According to X-ray photoelectron spectroscopy (XPS), after immobilization of PRP, up to 10.7 at % of nitrogen was incorporated into the nanofibers surface confirming the grafting of proteins. Active proliferation and sustaining the cell viability on nanofibers with immobilized PRP led to an average number of cells of 258 ± 12.9 and 364 ± 34.5 for nanofibers with ionic and covalent bonding of PRP, respectively. Hence, our new method for the modification of PCL nanofibers with PRP opens new possibilities for its application in tissue engineering. KW - polycaprolactone KW - nanofibers KW - COOH plasma KW - platelet-rich plasma KW - cell viability KW - PRP immobilization Y1 - 2017 UR - http://www.mdpi.com/2073-4360/9/12/736/htm U6 - https://doi.org/10.3390/polym9120736 SN - 2073-4360 VL - 9 IS - 12 ER - TY - GEN A1 - Kashkarov, Egor B. A1 - Nikitenkov, Nikolay A1 - Sutygina, Alina A1 - Obrosov, Aleksei A1 - Manakhov, Anton A1 - Polčak, Josef A1 - Weiß, Sabine T1 - Hydrogen absorption by Ti-implanted Zr-1Nb alloy T2 - International journal of hydrogen energy N2 - This paper describes the hydrogenation behavior of Zr-1Nb alloy Ti-implanted by plasma immersion ion implantation (PIII). Hydrogen sorption kinetics of the Ti-modified alloy was investigated under gas-phase hydrogenation at 400 °C for 1 h. The influence of implantation time on the protective properties of the modified layer was shown. The lowest hydrogen absorption as well as the highest hydrogen trapping efficiency was achieved after PIII for 30 min. The main contribution to the reduction of hydrogen permeation is the formation of an oxide layer consisting of mixed TiO2 and ZrO2 on the modified surface of the alloy. X-ray photoelectron spectroscopy (XPS) revealed that PIII titanium oxide exists on the surface in the form of TiO2, which transforms to mixed Ti2O3 and TiO2 after hydrogenation. The thickness of the modified layer increases with implantation time that improves the efficiency of hydrogen trapping. All the absorbed hydrogen is gradually distributed in the modified layer and no hydrides are formed after hydrogenation in Ti-modified Zr-1Nb for 15 and 30 min. KW - Zirconium KW - Titanium implantation KW - Hydrogenation KW - X-ray photoelectron spectroscopy KW - Glow discharge optical emission spectroscopy KW - X-ray diffraction Y1 - 2018 UR - https://www.sciencedirect.com/science/article/pii/S0360319917346359 U6 - https://doi.org/10.1016/j.ijhydene.2017.12.003 SN - 0360-3199 VL - 43 IS - 4 SP - 2484 EP - 2491 ER - TY - GEN A1 - Kashkarov, Egor B. A1 - Obrosov, Aleksei A1 - Sutygina, Alina A1 - Uludintceva, Elena A1 - Mitrofanov, Andrei A1 - Weiß, Sabine T1 - Hydrogen Permeation, and Mechanical and Tribological Behavior, of CrNx Coatings Deposited at Various Bias Voltages on IN718 by Direct Current Reactive Sputtering T2 - Coatings N2 - In the current work, the microstructure, hydrogen permeability, and properties of chromium nitride (CrNₓ) thin films deposited on the Inconel 718 superalloy using direct current reactive sputtering are investigated. The influence of the substrate bias voltage on the crystal structure, mechanical, and tribological properties before and after hydrogen exposure was studied. It was found that increasing the substrate bias voltage leads to densification of the coating. X-ray diffraction (XRD) results reveal a change from mixed fcc-CrN + hcp-Cr₂N to the approximately stoichiometric hcp-Cr₂N phase with increasing substrate bias confirmed by wavelength-dispersive X-ray spectroscopy (WDS). The texture coefficients of (113), (110), and (111) planes vary significantly with increasing substrate bias voltage. The hydrogen permeability was measured by gas-phase hydrogenation. The CrN coating deposited at 60 V with mixed c-CrN and (113) textured hcp-Cr₂N phases exhibits the lowest hydrogen absorption at 873 K. It is suggested that the crystal orientation is only one parameter influencing the permeation resistance of the CrNx coating together with the film structure, the presence of mixing phases, and the packing density of the structure. After hydrogenation, the hardness increased for all coatings, which could be related to the formation of a Cr₂O₃ oxide film on the surface, as well as the defect formation after hydrogen loading. Tribological tests reveal that hydrogenation leads to a decrease of the friction coefficient by up to 40%. The lowest value of 0.25 ± 0.02 was reached for the CrNₓ coating deposited at 60 V after hydrogenation. KW - CrNx coatings KW - Physical Vapour Deposition (PVD) KW - hydrogenation KW - tribology KW - mechanical properties KW - X-ray diffraction Y1 - 2018 UR - http://www.mdpi.com/2079-6412/8/2/66/htm U6 - https://doi.org/10.3390/coatings8020066 SN - 2079-6412 N1 - Special Issue "Surface Preparation and Treatments for Enhancing the Coating Performance" VL - 8 IS - 2 ER - TY - GEN A1 - Evdokimov, Anton A1 - Obrosov, Aleksei A1 - Ossenbrink, Ralf A1 - Weiß, Sabine A1 - Michailov, Vesselin T1 - Mechanical properties of dissimilar steel-aluminum weld T2 - Materials Science and Engineering: A N2 - Knowledge of the properties of dissimilar welds is of great significance for the development of multi-material lightweight structures. In this study, stainless steel (1.4301) and aluminum alloy (6082-T6) sheets were welded in overlap configuration in keyhole mode. The resulting weld metals were investigated with respect to their mechanical properties. Several samples were cut out of different locations along the welds and their cross-sections were subjected to indentation testing and energy dispersive X-ray (EDS) analysis. Young's modulus E, yield stress σy, and strain hardening exponent n, were determined by means of reverse analysis of the indentation load (P) – depth (h) curves, allowing construction of true stress – true strain relations. An essential increase in yield stress in comparison to the one of the base alloys was observed inside the weld metal. In contrary, Young's modulus and strain hardening exponent of the welds were almost identical to corresponding values of the base steel metal. Due to the sensitivity of yield stress to the aluminum content, slight variations of the welding parameters lead to significant changes in elastic-plastic behavior of the weld metal. KW - Mechanical properties KW - Indentation KW - Reverse analysis KW - EDS measurements KW - Dissimilar steel aluminum welding KW - FEM Y1 - 2018 UR - https://www.sciencedirect.com/science/article/pii/S0921509318303563 U6 - https://doi.org/https://doi.org/10.1016/j.msea.2018.03.019 SN - 0921-5093 VL - Volume 722 SP - 242 EP - 254 ER - TY - GEN A1 - Kashkarov, Egor B. A1 - Nikitenkov, Nikolay A1 - Sutygina, Alina A1 - Syrtanov, Maxim S. A1 - Zakharchenko, S. A1 - Obrosov, Aleksei T1 - Influence of Plasma-Immersion Titanium-Ion Implantation on the Kinetics of Hydrogen Penetration into E110 Zirconium Alloy T2 - Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques N2 - The influence of plasma-immersion titanium-ion implantation on the hydrogen saturation of E110 zirconium alloy is described. Titanium ions are implanted from the metal plasma of an arc discharge at an accelerating-pulse bias potential of 1.5 kV (the pulse-repetition frequency is 100 kHz, and the pulse length is 5 μs) for 30 min. The phase composition, morphology, and valence state of the alloy surface layer are studied. Comparative analysis of changes in the hardness and wear resistance of the alloy subjected to implantation is performed. It is demonstrated that the rate of hydrogen penetration into the surface-doped alloy decreases substantially at a gas-phase hydrogenation temperature of 400°C. KW - ion implantation KW - zirconium KW - titanium KW - hydrogen sorption KW - wear resistance KW - X-ray photoelectron spectroscopy Y1 - 2018 UR - https://link.springer.com/journal/11700 U6 - https://doi.org/10.1134/S102745101803031X SN - 1819-7094 VL - 12 IS - 3 SP - 570 EP - 575 ER - TY - GEN A1 - Petkov, Nikolay A1 - Kashkarov, Egor B. A1 - Obrosov, Aleksei A1 - Bakalova, Totka A1 - Kejzlar, Pavel A1 - Bahchedzhiev, Hristo T1 - Influence of Bias Voltage and CH4/N2 Gas Ratio on the Structure and Mechanical Properties of TiCN Coatings Deposited by Cathodic Arc Deposition Method T2 - Journal of Materials Engineering and Performance N2 - This article presents a study of the influence of the bias voltage and CH4/N2 gas ratio on the structure and mechanical properties of TiCN coatings. The coatings are deposited by cathodic arc deposition technology from Ti cathodes under an atmosphere of a mixture of CH4 and N2 gasses. XRD analysis shows that an increase in the methane flow changes the preferential orientation of the coating from (111) to (200) and results in a refinement of the structure (grain size reduction from 23 to 7 nm). SEM analysis shows that the coatings are stoichiometric. It was demonstrated that the bias voltage has an influence on the grain size, hardness and elasticity module. The highest hardness value of 52.5 GPa was measured at the coatings lacking a clear preferential orientation. The adhesion of the coatings showed a critical load in the range of 29-64 N. KW - cathodic arc deposition KW - nanohardness KW - TiCN coatings KW - XRD analysis Y1 - 2018 UR - https://link.springer.com/article/10.1007/s11665-018-3754-3 U6 - https://doi.org/10.1007/s11665-018-3754-3 SN - 1544-1024 SN - 1059-9495 VL - 28 IS - 1 SP - 343 EP - 354 ER - TY - GEN A1 - Obrosov, Aleksei A1 - Sutygina, Alina A1 - Kashkarov, Egor B. A1 - Weiß, Sabine T1 - Oxidation behavior of Zr–1Nb in air at 400°C after Titanium Plasma Immersion Ion Implantation N2 - Zirconium alloys have been widely used in nuclear reactors due to low thermal neutron capture cross-section, excellent corrosion resistance and acceptable mechanical properties [1, 2]. Nowadays several methods apply for improving hydrogen and corrosion resistance such as addition of stabilizing additives (yttrium) [3, 4], deposition of thin solid films [5, 6], micro-arc oxidation [7] and modification of the surface by electron beam [8, 9]. Despite the multiplicity of the methods hydrogen embrittlement is still a pressing issue. Previous results [10, 11] have shown the positive influence of plasma immersion titanium implantation on the hydrogenation behavior of Zr–1Nb and Zr–2.5 Nb. After Ti implantation hydrogen preferably accumulates in the modified surface layer comprising the implanted Ti. Furthermore, the hydrogen concentration is considerably less inside the zirconium modified sample than in the as-received samples. The integration of elements into the zirconium lattice can influence the valence of the surface and change corrosion and oxidation rates of the alloys. So it is very important not to decrease the zirconium oxidation resistance due to Ti implantation. Therefore, the purpose of this research is to study of the influence of Ti implantation on surface morphology, oxidation rate and phase structure of the Zr–1Nb alloy after oxidation on air at 400 0C for 5, 24, 72 and 240 h. The surface structure of the samples and their elemental composition were investigated with the scanning electron microscope Mira II XMH (Tescan) with energy dispersive x-ray spectroscopy system (EDS). X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC) as well as X-ray diffraction (XRD) was used to characterise the influence of titanium implantation on the oxidation behaviour. The results show that the oxidation kinetics after Ti modification of the zirconium alloy changed. Although the weight gain of the implanted sample remains approximately the same, it can be considered that Ti implantation stabilizes the oxide layer and has beneficial influence on the oxidation protection of Zr-1Nb. KW - Zr–1Nb KW - titanium ion implantation KW - oxidation KW - DSC KW - plasma immersion ion implantation (PIII) Y1 - 2018 UR - https://www.pse-conferences.net/tl_files/abstract-print/PSE2018-PO4029.pdf ER - TY - GEN A1 - Kashkarov, Egor B. A1 - Ryabchikov, Alexander I. A1 - Kurochkin, Alexander A1 - Syrtanov, Maxim S. A1 - Shevelev, Alexey A1 - Obrosov, Aleksei A1 - Weiß, Sabine T1 - Hydrogen Interaction with Deep Surface Modified Zr-1Nb Alloy by High Intensity Ti Ion Implantation T2 - Metals N2 - A deep surface modified TiZr layer was fabricated by high-intensity low-energy titanium ion implantation into zirconium alloy Zr-1Nb. Gas-phase hydrogenation was performed to evaluate protective properties of the modified layer against hydrogen permeation into Zr-1Nb alloy. The effects of ion implantation and hydrogen on microstructure, phase composition and elemental distribution of TiZr layer were analyzed by scanning electron microscopy, X-ray diffraction, and glow-discharge optical emission spectroscopy, respectively. It was revealed that TiZr layer (~10 μm thickness) is represented by α′ + α(TiZr) lamellar microstructure with gradient distribution of Ti through the layer depth. It was shown that the formation of TiZr layer provides significant reduction of hydrogen uptake by zirconium alloy at 400 and 500 °C. Hydrogenation of the modified layer leads to refinement of lamellar plates and formation of more homogenous microstructure. Hydrogen desorption from Ti-implanted Zr-1Nb alloy was analyzed by thermal desorption spectroscopy. Hydrogen interaction with the surface modified TiZr layer, as well as its resistance properties, are discussed. KW - zirconium alloy KW - titanium KW - low energy ion implantation KW - hydrogen KW - sorption KW - microstructure KW - morphology KW - martensitic phase Y1 - 2018 UR - https://www.mdpi.com/2075-4701/8/12/1081/htm U6 - https://doi.org/10.3390/met8121081 SN - 2075-4701 VL - 8 IS - 12 ER - TY - GEN A1 - Gunther, Victor A1 - Yasenchuk, Yuri A1 - Chekalkin, Timofey A1 - Marchenko, Ekaterina A1 - Gunther, Sergey A1 - Baigonakova, Gulsharat A1 - Hodorenko, Valentina A1 - Kang, Ji-hoon A1 - Weiß, Sabine A1 - Obrosov, Aleksei T1 - Formation of pores and amorphous-nanocrystalline phases in porous TiNi alloys made by self-propagating high-temperature synthesis (SHS) T2 - Advanced Powder Technology N2 - The objective of this study was to examine the mechanism how the surface of porous TiNi compounds produced by SHS method evolves. The prepared samples were investigated using light-microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive x-ray spectroscopy (EDS). The results indicated that the surface of all pores is represented by a granular stratum due to dendrite liquation by peritectic crystallization mechanism. The voids of 2–15 μm in size are formed owing to a capillary spreading of the liquid. Reaction gases with dissociated carbon, nitrogen, and oxygen are responsible for heat-and-mass transfer through the forming pores. High pressure-temperature effect of reaction gases on the melt causes the forming voids to coalesce, as well as transfers the peritectic liquid (PL) throughout the open pores catalyzing a distinctive spitted topography. It is through the chemisorption of gasiform nonmetallics by the pore surface melt, where these impurities are chemically bound, that it was formed a massive corrosion-resistant amorphous-nanocrystalline stratified shell deduced as an intermetallic oxycarbonitride layer. KW - Porous TiNi alloys KW - SHS KW - Pore formation KW - Surface structures KW - Heat-and-mass transfer Y1 - 2019 UR - https://www.sciencedirect.com/science/article/pii/S092188311830387X?via%3Dihub U6 - https://doi.org/10.1016/j.apt.2018.12.011 SN - 0921-8831 VL - 30 IS - 4 SP - 673 EP - 680 ER - TY - GEN A1 - Kashkarov, Egor B. A1 - Syrtanov, Maxim S. A1 - Murashkina, Tatyana A1 - Kurochkin, Alexander A1 - Shanenkova, Yulia A1 - Obrosov, Aleksei T1 - Hydrogen Sorption Kinetics of SiC-Coated Zr-1Nb Alloy T2 - Coatings N2 - This paper describes the influence of silicon carbide (SiC) coating on hydrogen sorption kinetics of zirconium alloy E110 (Zr-1Nb). Amorphous SiC coating of 1.5-μm thickness was deposited on Zr-1Nb alloy substrate by direct current magnetron sputtering of composite cathode. Hydrogen absorption by SiC-coated Zr-1Nb alloy significantly decreased due to low hydrogen permeability of the coating. Hydrogenation tests show that SiC coating provides protective properties against hydrogen permeation in the investigated temperature range of 350–450 °C. It was shown that hydrogenation of uncoated Zr-1Nb leads to formation of δ hydrides at 350 °C and δ and γ hydrides at higher temperatures whereas in the SiC-coated Zr-1Nb alloy only δ hydrides formed. Gradient hydrogen distribution through the SiC coating and H trapping in the carbon-rich interface was observed. The adhesion strength of the coating was ~5 N. Hydrogenation up to 450 °C for 5 h does not degrade the adhesion properties during scratch testing. KW - hydrogen sorption KW - hydrogenation KW - zirconium alloys KW - E110 (Zr-1Nb) KW - SiC coating KW - magnetron sputtering KW - adhesion Y1 - 2019 UR - https://www.mdpi.com/2079-6412/9/1/31 U6 - https://doi.org/10.3390/coatings9010031 SN - 2079-6412 VL - 9 IS - 1 ER - TY - GEN A1 - Yasenchuk, Yuri A1 - Gunther, Victor A1 - Marchenko, Ekaterina A1 - Chekalkin, Timofey A1 - Baigonakova, Gulsharat A1 - Hodorenko, Valentina A1 - Gunther, Sergey A1 - Kang, Ji-hoon A1 - Weiß, Sabine A1 - Obrosov, Aleksei T1 - Formation of mineral phases in self-propagating high-temperature synthesis (SHS) of porous TiNi alloy T2 - Materials Research Express N2 - The complex structural-phase composition, morphology and elemental composition of surface and nonmetallics in porous TiNi compounds produced by self-propagating high-temperature synthesis (SHS) in a flow reactor in the layer-by-layer combustion mode were analyzed. The samples were investigated using light microscopy (LM), X-ray diffraction (XRD), scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), and energy dispersive X-ray spectroscopy (EDS). The findings indicate that in addition to the TiNi and Ti2Ni intermetallic constituents, the pore's surface contains numerous Ti4Ni2(O,N,C) nanocrystalline oxycarbonitrides, spinels, polysilicates, and residual amorphous phases. The elemental composition of the surface and crystalline inclusions is investigated by the EDS method. LM, SEM, TEM, and EDS instrumental examination revealed the entire surface comprising a continuous shell of intermetallic superficial bulb-shaped structures, as well as crystalline inclusions of polysilicates and spinels in the intergranular peritectic phase. Prominent morphology was confirmed to appear throughout the pore's surface owing to the interaction of the peritectic liquid (PL) with reaction gases. The epitaxial, nanocrystalline strata of intermetallic oxycarbonitrides were shown to have the intricate nature. Reaction gases chemisorbed by the PL are responsible for the continuous and dense substrate, which ultrafine structure modulates a high corrosion resistance. On the contrary, the sparse and foamy overlay resulted from a convective transfer of the PL by reaction gases facilitates in vivo bio-integration of the alloy. Overall, this sheds light on and may be more indicative of the complex role of superficial strata and nonmetallic crystals in enhanced biocompatibility of the unwrought porous TiNi alloy. KW - Porous TiNi alloys KW - SHS KW - Pore formation KW - Surface structures KW - Reaction gases KW - Amorphous layer Y1 - 2019 UR - https://iopscience.iop.org/article/10.1088/2053-1591/ab01a1 U6 - https://doi.org/10.1088/2053-1591/ab01a1 SN - 2053-1591 VL - 6 IS - 5 ER - TY - GEN A1 - Shtin, Valentin A1 - Novikov, Valeriy A1 - Chekalkin, Timofey A1 - Gunther, Victor A1 - Marchenko, Ekaterina A1 - Choynzonov, Evgeniy A1 - Baik Kang, Seung A1 - Jong Chang, Moon A1 - Hoon Kang, Ji A1 - Obrosov, Aleksei T1 - Repair of Orbital Post-Traumatic Wall Defects by Custom-Made TiNi Mesh Endografts T2 - Journal of Functional Biomaterials N2 - Repairs of orbital post-traumatic and extensive malignant defects remain a major surgical challenge, in view of follow-up outcomes. Incorrect surgical management of injured facial structures results in cosmetic, ophthalmic, and social aftereffects. A custom-made knitted TiNi-based mesh (KTNM) endograft was employed to overcome post-surgical complications and post-resected lesions of the orbital area. Preoperative high-resolution computed tomography (CT) imaging and CAD modelling were used to design the customized KTNM in each case. Twenty-five patients underwent surgery utilizing the suggested technique, from 2014 to 2019. In all documented cases, resolution of the ophthalmic malfunction was noted in the early period. Follow-up observation evidenced no relapsed enophthalmos, hypoglobus, or diplopia as late complications. The findings emanating from our clinical observations allow us to claim that the KTNM indicated a high level of biocompatibility. It is simply modified intraoperatively to attach any desired shape/size for implantation and can also be screw-fixed, providing a good supporting ability. The KTNM precisely renders orbitozygomatic outlines and orbital floor, thus recovering the anatomical structure, and is regarded as an attractive alternative to Ti-based meshes and plates. Additionally, we report one of the studied cases, where good functional and cosmetic outcomes have been achieved. KW - diplopia KW - enophthalmos KW - orbital defect repair KW - TiNi mesh Y1 - 2019 UR - https://www.mdpi.com/2079-4983/10/3/27 U6 - https://doi.org/10.3390/jfb10030027 SN - 2079-4983 VL - 10 IS - 3 ER - TY - GEN A1 - Ryabchikov, Alexander I. A1 - Kashkarov, Egor B. A1 - Shevelev, Alexey A1 - Obrosov, Aleksei A1 - Sivin, D. O. T1 - Surface modification of Al by high-intensity low-energy Ti-ion implantation: Microstructure, mechanical and tribological properties T2 - Surface and Coatings Technology N2 - A high-intensity metal ribbon ion beam was generated using plasma immersion extraction and the acceleration of the metal ions with their subsequent ballistic focusing using a cylindrical grid electrode under a repetitively pulsed bias. To generate the dense metal plasma flow, two water-cooled vacuum arc evaporators with Ti cathodes were used. The ion current density reached 43 mA/cm2 at the arc discharge current of 130 A. High-intensity ion implantation (HIII) with a low ion energy ribbon beam was used for the surface modification of the aluminium. The irradiation fluence was changed from 1.5 × 1020 ion/cm2 to 4 × 1020 ion/cm2 with a corresponding increase in the implantation temperature from 623 to 823 K. The structure and composition of the Ti-implanted aluminium were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX). The mechanical properties and wear resistance were measured using nanoindentation and “pin-on-disk” testing, respectively. It was shown that the HIII method can be used to form a deep intermetallic Al3Ti layer. It has been established that a thin (0.4 μm) modified layer with a hcp Ti(Al) structure is only formed on the surface at 623 K, while the formation of the ordered Al3Ti intermetallic phase occurs at the implantation temperatures of 723 and 823 K. Despite the significant ion sputtering of the surface, the thickness of the modified layer increases from ~1 μm to ~6 μm, and the implantation temperature rises from 723 to 823 K. It was found that the homogeneous intermetallic Al3Ti layer with a thickness of up to 5 μm was formed at 823 К. The mechanical and tribological properties of the aluminium were substantially improved after HIII. For the Ti-implanted aluminium, the hardness of the surface layer increases from 0.4 GPa (undoped Al) to 3.5–4 GPa, while the wear resistance increases by more than an order of magnitude. KW - Ion implantation KW - Ribbon ion beam KW - Intermetallics KW - Aluminium KW - Titanium KW - Surface modification Y1 - 2019 UR - https://www.sciencedirect.com/science/article/pii/S0257897219304992?via%3Dihub U6 - https://doi.org/10.1016/j.surfcoat.2019.05.020 SN - 0257-8972 VL - 372 SP - 1 EP - 8 ER -