AbstractThe goal of this work was to study nitrogen implantation from plasma with the aim of app... more AbstractThe goal of this work was to study nitrogen implantation from plasma with the aim of applying it in dual gate oxide technology and to examine the influence of the rf power of plasma and that of oxidation type. The obtained structures were examined by means of ...
It is known that the degree of ionization of the coating precursors is one of the key factors in ... more It is known that the degree of ionization of the coating precursors is one of the key factors in a control of the structure and properties of sputter deposited carbon-based coatings. Numerous modifications of a conventional magnetron sputtering technique were elaborated in order to increase the degree of plasma ionization. The most effective of them were based on an application of an additional source of plasma excitation, independent of magnetron discharge. This paper presents results of the investigations of nc-WC/a-C(:H) coatings, deposited by means of magnetron sputtering of graphite and tungsten targets, enhanced by an additional radio-frequency discharge of a maximum power of 150 W, limited to a volume directly adjacent to the specimens. In order to assess thickness, surface morphology and chemical composition of the coatings, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) techniques were used, while Raman Shift Spectroscopy (RSS) together with XPS was applied to determine the types of bonds between carbon atoms. Tribological properties of the coatings were investigated using a 'pin-on-disc' method, with the friction couple comprising bearing steel counterbody. It has been found that additional RF discharge has a significant effect on the type of bonds of carbon atoms in the coating. In the case of non-hydrogenated nc-WC/ a-C coatings, an introduction of additional RF discharge caused an increase of a contribution of sp 3 hybridized carbon atoms by 32%, as well as an increase of friction coefficient. The highest share of sp 3 hybridization was obtained in the case of hydrogenated nc-WC/a-C:H coatings deposited in Ar + CH 4 atmosphere with an enhancement of additional RF discharge maintained at 150 W of power. These conditions brought about a decreased friction coefficient (to a value of 0.05) and a decreased wear rate (to an approximate value of 10 −17 m 3 N −1 m −1).
New Superhard coatings based on Ti-Hf-Si-N featuring high physical and mechanical properties were... more New Superhard coatings based on Ti-Hf-Si-N featuring high physical and mechanical properties were fabricated. We employed a vacuum-arc source with HF stimulation and a cathode sintered from Ti-Hf-Si. Nitrides were fabricated using atomic nitrogen (N) or a mixture of Ar/N, which were leaked-in a chamber at various pressures and applied to a substrate potentials. RBS, SIMS, GT-MS, SEM with EDXS, XRD, and nanoindentation were employed as analyzing methods of chemical and phase composition of thin films. We also tested tribological and corrosion properties. The resulting coating was a two-phase, nanostructured nc-(Ti, Hf)N and �. -Si3N4. Sizes of substitution solid solution nanograins changed from 3.8 to 6.5 nm, and an interface thickness surrounding �. -Si3N4 varied from 1.2 to 1.8 nm. Coatings hardness, which was measured by nanoindentation was from 42.7 GPa to 48.6 GPa, and an elastic modulus was E = (450 to 515) GPa. The films stoichiometry was defined for various deposition conditi...
Multilayered nanostructured coatings consisting of MoN and CrN alternating layers have been consi... more Multilayered nanostructured coatings consisting of MoN and CrN alternating layers have been considered. The coatings obtained by arc-vacuum deposition in 3 series with different bias potential. The thickness of bilayers has been varied from micro (1.73 μm) to nanosizes (36÷41 nm). Parameters of deposition have been changed, such as bias potential from −20 V to −300 V and chamber pressure from 7×10<sup>−4</sup> to 3×10<sup>−3</sup> Torr. An element and structural analysis performed with XRD, SEM (with EDS), RBS, SIMS methods has shown well properties of obtained coatings, with clearly allocated layers of CrN and MoN. It is found formation of mononitride CrN and Mo<inf>2</inf>N with cubic lattice NaCl-type. Decreasing of bilayers thickness to (36÷41) nm has provided high hardness (38÷42) GPa and wear resistance. Remarkable that increasing of chamber pressure leads to increase of wear resistance.
Simple and compact design of prototype electron beam welding machine is presented. The instrument... more Simple and compact design of prototype electron beam welding machine is presented. The instrument allows welding of typical materials as metals and alloys. It can be used also for surface melting of insulators like glass and ceramic. Electron beam source uses hollow cathode of 20 mm diameter and operates in the pressure between 0.001 to 0.1 Torr of noble gas, with the work-piece positioned at 30 mm distance from the cathode. Focussing of the electron beam is provided by curvature and shape of the cathode surface. No magnetic focussing is provided. Applied voltage to the cathode is in the range 1 – 3 kV, so the energy of electrons is much lower than in conventional electron beam welders. The presence of working gas in the chamber and the occurrence of accompanying glow discharge allows for surface charge neutralization. This causes that the electron beam can bombard insulating materials. The prototype construction of welder does not require complicated and expensive pumping system. I...
Abstract Nanocomposites based on hard compounds are currently on the stage of active research and... more Abstract Nanocomposites based on hard compounds are currently on the stage of active research and development. Hence the analysis of a relation between nanostructure and functional properties are of great importance. The main purpose of the study was to assess the stoichiometry effect on the finite characteristics of TiZrC nanocomposite coatings. This paper presents the analysis of the Ti1-xZrxC (x = 0, 0.25, 0.5, 0.75 and 1.0) hard coatings sputtered onto Si substrates by a two-target DC magnetron. It has been found that the increase of carbon content in the bulk of the coatings contributes to the structural changes, namely, lead to the formation of the nc-Ti1-xZrxCy/a-C nanocomposite structure with (Ti,Zr)C solid-solution phase which is in a good agreement to theoretical predictions. Electrical properties measurements have shown infrequent results concerning intrinsic conductivity, which can prosper this system application for a new generation of nano and microsystems. The analysis reveals the nature of tunnelling conductance between the nanoparticles. On the computer simulation of the frequency dependence of the frequency coefficient, three maxima were discovered. Two of them were attributed to dominant phases (Ti1-xZrx)C and amorphous carbon (a-C). The third one is related to the content of another type of nanophase that, due to low content, could not be determined by structural methods. Mechanical tests showed promising results in suitability to micromechanical devices, in particular: sensors, actuators, power-producing devices. These findings establish an understanding of microstructural regularities and enlarge the potential application space for TiZrC-based systems.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2019
Secondary ion mass spectrometry (SIMS) is a very useful technique for the analysis of layered sys... more Secondary ion mass spectrometry (SIMS) is a very useful technique for the analysis of layered systems. It is based on the primary ion beam sputtering of solids and mass analysis of the emitted secondary ions. A main limitation of this technique results from the direct quantitative analysis, since the ionization efficiency of a given atom is highly influenced by the neighbouring atoms at the surface. This phenomenon is known as the 'matrix effect'. This problem can be partially solved by separation of the sputtering and ionization processes. The 'Storing Matter' technique involves deposition of the sputtered matter onto a rotating collector. Subsequently, ionisation occurs during the ion beam bombardment of the stored matter. In case of sputtering of a given layered structure, the stored matter deposit presents the sequence of the deposition process and the analysis of this deposit reflects the investigated structure. We analyse a set of on oxidized steel samples and oxidized steel covered by aluminium. These types of structures are known for strong matrix effects at the metal oxide interfaces. The results of the 'Storing Mater' analyses are compared with the results of the classical SIMS analysis.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2016
Multielement high entropy alloy (HEA) nitride (TiHfZrNbVTa)N coatings were deposited by vacuum ar... more Multielement high entropy alloy (HEA) nitride (TiHfZrNbVTa)N coatings were deposited by vacuum arc and their structural and mechanical stability after implantation of high doses of N + ions, 10 18 cm À2 , were investigated. The crystal structure and phase composition were characterized by X-ray diffraction (XRD) and Transmission Electron Microscopy, while depth-resolved nanoindentation tests were used to determine the evolution of hardness and elastic modulus along the implantation depth. XRD patterns show that coatings exhibit a main phase with fcc structure, which preferred orientation varies from (1 1 1) to (2 0 0), depending on the deposition conditions. First-principles calculations reveal that the presence of Nb atoms could favor the formation of solid solution with fcc structure in multielement HEA nitride. TEM results showed that amorphous and nanostructured phases were formed in the implanted coating sub-surface layer ($100 nm depth). Concentration of nitrogen reached 90 at% in the near-surface layer after implantation, and decreased at higher depth. Nanohardness of the as-deposited coatings varied from 27 to 38 GPa depending on the deposition conditions. Ion implantation led to a significant decrease of the nanohardness to 12 GPa in the implanted region, while it reaches 24 GPa at larger depths. However, the H/E ratio is P0.1 in the sub-surface layer due to N + implantation, which is expected to have beneficial effect on the wear properties.
AbstractThe goal of this work was to study nitrogen implantation from plasma with the aim of app... more AbstractThe goal of this work was to study nitrogen implantation from plasma with the aim of applying it in dual gate oxide technology and to examine the influence of the rf power of plasma and that of oxidation type. The obtained structures were examined by means of ...
It is known that the degree of ionization of the coating precursors is one of the key factors in ... more It is known that the degree of ionization of the coating precursors is one of the key factors in a control of the structure and properties of sputter deposited carbon-based coatings. Numerous modifications of a conventional magnetron sputtering technique were elaborated in order to increase the degree of plasma ionization. The most effective of them were based on an application of an additional source of plasma excitation, independent of magnetron discharge. This paper presents results of the investigations of nc-WC/a-C(:H) coatings, deposited by means of magnetron sputtering of graphite and tungsten targets, enhanced by an additional radio-frequency discharge of a maximum power of 150 W, limited to a volume directly adjacent to the specimens. In order to assess thickness, surface morphology and chemical composition of the coatings, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) techniques were used, while Raman Shift Spectroscopy (RSS) together with XPS was applied to determine the types of bonds between carbon atoms. Tribological properties of the coatings were investigated using a 'pin-on-disc' method, with the friction couple comprising bearing steel counterbody. It has been found that additional RF discharge has a significant effect on the type of bonds of carbon atoms in the coating. In the case of non-hydrogenated nc-WC/ a-C coatings, an introduction of additional RF discharge caused an increase of a contribution of sp 3 hybridized carbon atoms by 32%, as well as an increase of friction coefficient. The highest share of sp 3 hybridization was obtained in the case of hydrogenated nc-WC/a-C:H coatings deposited in Ar + CH 4 atmosphere with an enhancement of additional RF discharge maintained at 150 W of power. These conditions brought about a decreased friction coefficient (to a value of 0.05) and a decreased wear rate (to an approximate value of 10 −17 m 3 N −1 m −1).
New Superhard coatings based on Ti-Hf-Si-N featuring high physical and mechanical properties were... more New Superhard coatings based on Ti-Hf-Si-N featuring high physical and mechanical properties were fabricated. We employed a vacuum-arc source with HF stimulation and a cathode sintered from Ti-Hf-Si. Nitrides were fabricated using atomic nitrogen (N) or a mixture of Ar/N, which were leaked-in a chamber at various pressures and applied to a substrate potentials. RBS, SIMS, GT-MS, SEM with EDXS, XRD, and nanoindentation were employed as analyzing methods of chemical and phase composition of thin films. We also tested tribological and corrosion properties. The resulting coating was a two-phase, nanostructured nc-(Ti, Hf)N and �. -Si3N4. Sizes of substitution solid solution nanograins changed from 3.8 to 6.5 nm, and an interface thickness surrounding �. -Si3N4 varied from 1.2 to 1.8 nm. Coatings hardness, which was measured by nanoindentation was from 42.7 GPa to 48.6 GPa, and an elastic modulus was E = (450 to 515) GPa. The films stoichiometry was defined for various deposition conditi...
Multilayered nanostructured coatings consisting of MoN and CrN alternating layers have been consi... more Multilayered nanostructured coatings consisting of MoN and CrN alternating layers have been considered. The coatings obtained by arc-vacuum deposition in 3 series with different bias potential. The thickness of bilayers has been varied from micro (1.73 μm) to nanosizes (36÷41 nm). Parameters of deposition have been changed, such as bias potential from −20 V to −300 V and chamber pressure from 7×10<sup>−4</sup> to 3×10<sup>−3</sup> Torr. An element and structural analysis performed with XRD, SEM (with EDS), RBS, SIMS methods has shown well properties of obtained coatings, with clearly allocated layers of CrN and MoN. It is found formation of mononitride CrN and Mo<inf>2</inf>N with cubic lattice NaCl-type. Decreasing of bilayers thickness to (36÷41) nm has provided high hardness (38÷42) GPa and wear resistance. Remarkable that increasing of chamber pressure leads to increase of wear resistance.
Simple and compact design of prototype electron beam welding machine is presented. The instrument... more Simple and compact design of prototype electron beam welding machine is presented. The instrument allows welding of typical materials as metals and alloys. It can be used also for surface melting of insulators like glass and ceramic. Electron beam source uses hollow cathode of 20 mm diameter and operates in the pressure between 0.001 to 0.1 Torr of noble gas, with the work-piece positioned at 30 mm distance from the cathode. Focussing of the electron beam is provided by curvature and shape of the cathode surface. No magnetic focussing is provided. Applied voltage to the cathode is in the range 1 – 3 kV, so the energy of electrons is much lower than in conventional electron beam welders. The presence of working gas in the chamber and the occurrence of accompanying glow discharge allows for surface charge neutralization. This causes that the electron beam can bombard insulating materials. The prototype construction of welder does not require complicated and expensive pumping system. I...
Abstract Nanocomposites based on hard compounds are currently on the stage of active research and... more Abstract Nanocomposites based on hard compounds are currently on the stage of active research and development. Hence the analysis of a relation between nanostructure and functional properties are of great importance. The main purpose of the study was to assess the stoichiometry effect on the finite characteristics of TiZrC nanocomposite coatings. This paper presents the analysis of the Ti1-xZrxC (x = 0, 0.25, 0.5, 0.75 and 1.0) hard coatings sputtered onto Si substrates by a two-target DC magnetron. It has been found that the increase of carbon content in the bulk of the coatings contributes to the structural changes, namely, lead to the formation of the nc-Ti1-xZrxCy/a-C nanocomposite structure with (Ti,Zr)C solid-solution phase which is in a good agreement to theoretical predictions. Electrical properties measurements have shown infrequent results concerning intrinsic conductivity, which can prosper this system application for a new generation of nano and microsystems. The analysis reveals the nature of tunnelling conductance between the nanoparticles. On the computer simulation of the frequency dependence of the frequency coefficient, three maxima were discovered. Two of them were attributed to dominant phases (Ti1-xZrx)C and amorphous carbon (a-C). The third one is related to the content of another type of nanophase that, due to low content, could not be determined by structural methods. Mechanical tests showed promising results in suitability to micromechanical devices, in particular: sensors, actuators, power-producing devices. These findings establish an understanding of microstructural regularities and enlarge the potential application space for TiZrC-based systems.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2019
Secondary ion mass spectrometry (SIMS) is a very useful technique for the analysis of layered sys... more Secondary ion mass spectrometry (SIMS) is a very useful technique for the analysis of layered systems. It is based on the primary ion beam sputtering of solids and mass analysis of the emitted secondary ions. A main limitation of this technique results from the direct quantitative analysis, since the ionization efficiency of a given atom is highly influenced by the neighbouring atoms at the surface. This phenomenon is known as the 'matrix effect'. This problem can be partially solved by separation of the sputtering and ionization processes. The 'Storing Matter' technique involves deposition of the sputtered matter onto a rotating collector. Subsequently, ionisation occurs during the ion beam bombardment of the stored matter. In case of sputtering of a given layered structure, the stored matter deposit presents the sequence of the deposition process and the analysis of this deposit reflects the investigated structure. We analyse a set of on oxidized steel samples and oxidized steel covered by aluminium. These types of structures are known for strong matrix effects at the metal oxide interfaces. The results of the 'Storing Mater' analyses are compared with the results of the classical SIMS analysis.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2016
Multielement high entropy alloy (HEA) nitride (TiHfZrNbVTa)N coatings were deposited by vacuum ar... more Multielement high entropy alloy (HEA) nitride (TiHfZrNbVTa)N coatings were deposited by vacuum arc and their structural and mechanical stability after implantation of high doses of N + ions, 10 18 cm À2 , were investigated. The crystal structure and phase composition were characterized by X-ray diffraction (XRD) and Transmission Electron Microscopy, while depth-resolved nanoindentation tests were used to determine the evolution of hardness and elastic modulus along the implantation depth. XRD patterns show that coatings exhibit a main phase with fcc structure, which preferred orientation varies from (1 1 1) to (2 0 0), depending on the deposition conditions. First-principles calculations reveal that the presence of Nb atoms could favor the formation of solid solution with fcc structure in multielement HEA nitride. TEM results showed that amorphous and nanostructured phases were formed in the implanted coating sub-surface layer ($100 nm depth). Concentration of nitrogen reached 90 at% in the near-surface layer after implantation, and decreased at higher depth. Nanohardness of the as-deposited coatings varied from 27 to 38 GPa depending on the deposition conditions. Ion implantation led to a significant decrease of the nanohardness to 12 GPa in the implanted region, while it reaches 24 GPa at larger depths. However, the H/E ratio is P0.1 in the sub-surface layer due to N + implantation, which is expected to have beneficial effect on the wear properties.
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Papers by Piotr Konarski