PVD Method Research Articles

Maximizing efficiency in C45 steel machining: an integrated AI-based approach to coated insert optimization

AbstractMachining involves the subtraction of the material from the sample workpiece to achieve the desired shape or surface. This versatile method is capable of producing a wide range of parts, varying from simple to intricate profiles. Coating materials are increasingly being utilized in tool inserts in the production industry owing to their superior thermal properties and wear resistance. The shielding of hard coatings, with thicknesses of only a few microns, enhances performance and durability. In this study, machining of C45 steel using distinct coated inserts was explored. The experimental trials employed PVD and CVD methods for coated tungsten carbide (WC) tools/inserts and PVD-coated cermet tools/inserts with different machining parameters. Performance metrics, such as the surface finish and reliability of the tool, were considered for the evaluation. The average tool life variation between the PVD-coated cermet and PVD-coated WC was 178.86%, and 30.11% between the PVD-coated cermet and CVD-coated WC at 1 mm DOC. ANOVA was performed using Response Surface Methodology to explore the influence of input parameters on output. The results indicate that the depth of machining and spindle speed significantly influence Ra, whereas spindle speed and type of tool insert have a considerable impact on the life span of the tool. The developed mathematical model for the prediction of tool life and Ra indicates its potential for performance forecasting during C45 steel machining. Grey relation analysis was employed to optimize the process parameters. Optimal results were achieved with a spindle speed of 400 m/min, 0.5 mm depth of cut, and cermet tool inserts. PVD-coated WC inserts performed better. ANFIS was applied for the prediction and optimization of the machining parameters.

Investigation of Wear, Surface, Metallurgical and Mechanical Properties of Ti6Al4V Alloys Coated with PVD Method

Investigation of Wear, Surface, Metallurgical and Mechanical Properties of Ti6Al4V Alloys Coated with PVD Method

The Preparation and Properties of a Hydrogen-Sensing Field-Effect Transistor with a Gate of Nanocomposite C-Pd Film

The objective of this paper is to evaluate the effect of a nanostructured C-Pd film deposited in the gate area of a field-effect transistor (FET) with a carbon–palladium composite gate (C-Pd/FET) on the hydrogen-sensing properties of the transistor. The method of preparing a field-effect transistor (FET) with a C-Pd film deposited as a gate and the properties of such a transistor and the film itself are presented. The C-Pd film deposited by PVD method on the gate area serves as an active layer. The PVD process was carried out in a dynamic vacuum of 10−5 mbar from two separated sources—one containing fullerenes (C60) and the other containing palladium acetate. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS, EDX) and electrical property studies were used to the characterize C-Pd films and FET/C-Pd structures. SEM observations revealed the topography of C-Pd films and FET/C-Pd transistors. EDS/EDX microanalysis was applied to visualize the arrangement of elements on the studied surfaces. The changes in electrical properties (resistance and relative resistance) due to the presence of hydrogen were studied in a designed and computerized experimental set-up. The enhanced properties of the FET/C-Pd transistor are demonstrated in terms of hydrogen detection.

Thermally stimulated desorption from the surface of black aluminum layers prepared by PVD methods

Black aluminum is characterized by a highly granular structure and porous surface - i.e. the real surface area is several times larger than its geometric projection to the substrate. In addition, it is a metal with good surface gas sorption capacity and structural stability up to temperatures T ∼500 °C.The surface exchange interactions between the ambient environment and thin layers of black aluminum prepared by different methods are described. These properties are convenient for materials that are suitable for the fabrication of active layers of chemiresistors. The layers were prepared by magnetron sputtering at room temperature and liquid nitrogen temperature, and evaporation with different compositions and gas flow rates. In this work, the process of thermally stimulated desorption was measured using mass spectrometry. The calculation of the activation energy Eact for the release of individual desorbing atoms, or radicals, from the surface of black aluminum was performed. Knowing of the temperature and the number of particles released by desorption allows us to get an idea of the number of defects and the functionalized structure of the surface layer.

The Influence of nc-AlCrTiN/α-BN Coatings on Increasing the Durability of WC/Co Cutting Inserts in the Inconel Alloy Machining Process.

Anti-wear coatings obtained through PVD methods may significantly increase the durability of cutting tools by impacting their wear mechanisms. This study presents and discusses the results of studies on the impact of the thermal conductivity of PVD coatings on the intensity of the built-up edge (BUE) and built-up layer (BUL) formation in Inconel 600 alloy machining processes. The authors determine the microstructure, phase structure, mechanical properties (hardness, Young's modulus, and adhesion), and thermal conductivity of different PVD coatings selected for the purpose of the study and varying in terms of conductivity-i.e., AlCrTiN and AlCrTiN/BN. Machining processes were carried out under controlled conditions using VBGT160404-M3 cutting inserts with AlCrTiN and AlCrTiN/BN coatings deposited on their surface. The authors prove that the adjustment of the thermal conductivity of PVD coatings to the thermal conductivity of the tool and machined materials can help change the direction of heat flow to cool the cutting zone more effectively. The study results presented in this article show that the deposition of the AlCrTiN/BN coating reduces the friction wear on the tool flank by over 70% and lowers the intensity of BUE and BUL formation processes on the face by 10%, compared to the AlCrTiN coating.

An investigation of the corrosion behavior of zinc-coated stainless steel orthodontic wires: the effect of physical vapor deposition method

BackgroundReleasing of metal ions might implicate in allergic reaction as a negative subsequent of the corrosion of Stainless Steel (SS304) orthodontic wires. The aim of this study was to evaluate the corrosion resistance of zinc-coated (Zn-coated) SS orthodontic wires.MethodsZinc coating was applied on SS wires by PVD method. Electrochemical impedance spectroscopy (EIS), Potentiodynamic polarization tests and Tafel analysis methods were used to predict the corrosion behavior of Zn-coated and uncoated SS wires in both neutral and acidic environments.ResultsThe values of Ecorr ,icorr and Rct ,which were the electrochemical corrosion characteristics, reported better corrosion behavior of Zn-coated SS wires against uncoated ones in both artificial saliva and fluoride-containing environments. Experimental results of the Tafel plot analyses were consistent with that of electrochemical impedance spectroscopy analyses for both biological solutions.ConclusionApplying Zn coating on bare SS orthodontic wire by PVD method might increase the corrosion resistance of the underlying stainless-steel substrate.

Root cause analysis of coining tool failure with proposed solution to extend its service life

The article deals with a root cause analysis of coining tool failure after its untimely discarding and the design to extend its service life by innovating the manufacturing process. The analysis was performed on the coining die which had to be put out of service due to the insufficient quality of minted stainless coins. The purity of steel and the microstructure of the material of the semi-finished goods were evaluated. Furthermore, an analysis of the coining die failure under the surface and in the core was performed as well as the state of the chromium layer failure on the coining die relief. Based on the results of the analysis, a new experimental coining die was designed and produced according to an innovative manufacturing process. The pressing of the relief was carried out in a vacuum furnace and relief was coated with a TiAlN by the PVD method. New processes introduced in the production of coining die prevented the failure of die punches, extended the time of operation, thereby increasing quality of the coin production.

Investigation of Residual Stress Behavior of TiN Coating Film on Automotive Spring Steel using Multi-arc PVD Method

Investigation of Residual Stress Behavior of TiN Coating Film on Automotive Spring Steel using Multi-arc PVD Method

Electrical transport properties of Cu2ZnSnSe4 thin films for solar cells applications

In this work we study the electrical transport properties of Cu2ZuSnSe4 (CZTse) thin films. CZTSe thin films were prepared by PVD method; the parameters of deposition as substrate temperature (T,) and mass, (Mx), (Mx = ZnSe, Cu) were varied for a range wide. Conductivity and resistivity measurements as a function of temperature were obtained between 120 and 400 K. It was observed, that high-temperature range above room temperature (>300 K) the carrier transport is thermally activated, with a single activation energy that changes with the variation of T, and Mx. In the low-temperature range (<300 K)), variable range hopping (VRH) was established as a predominant electronic transport mechanism for all samples. Hoppmg parameters were obtained by Difíusinal model and percolation theory.

Tribological Properties of a Sliding Joint with an a-C:H:W Coating under Lubrication Conditions with PAO8 Oil and the Addition of 2% MoS2 Nanoparticles.

One of the promising methods for improving the durability and reliability of friction joints in combustion engines is the use of thin and hard coatings, including coatings based on amorphous DLC. The a-C:H:W coating was produced using the commercial PVD method. The tested tribological joints were made of AISI 4337 steel and SAE-48 bearing alloy (conformal contact) and AISI 4337 steel and valve shims (non-conformal contact). The contact area was lubricated with SAE 5W40 engine oil and PAO8 oil + 2 wt.% MoS2 nanoparticles. The objective of this work is to explore the influence of PAO8 + MoS2 on the tribological properties of a sliding joint with an a-C:H:W coating and the change in the properties of the oils. In the conformal contact, the lubrication of the a-C:H:W coating with PAO8 + MoS2 caused a significant increase in the friction resistance (than in) as compared to the joints with a quenching and tempering surface layer and lubricated SAE 5W40, while in the non-conformal contact, the lubrication of the a-C:H:W coating with PAO8 + MoS2 caused a decrease in the friction resistance and temperature of the contact area. The joints with the a-C:H:W coating were characterized by higher wear of the SAE-48 bearing alloy, as compared to the joints with the surface layer without coating (lubricated with SAE 5W40 oil-11-fold increase, PAO8 + MoS2-46-fold increase). The wear of valve shims with the a-C:H:W coating was significantly lower as compared to the wear of the commercial version of the valve shims (the difference between joints lubricated with SAE 5W40 oil and PAO8 + MoS2 was 12%, 36% and 29% for unit pressures of 10, 15 and 20 MPa). Lubrication of the a-C:H:W coating with PAO8 oil + MoS2 protected the sliding joints against seizing in non-conformal contact.

Effects of VCN coating of PEEK gears with the PVD method on wear performance

Effects of VCN coating of PEEK gears with the PVD method on wear performance

Chromium nanostructured coatings formed by the PVD method

Chromium nanostructured coatings formed by the PVD method

Thermally stimulated exoelectron emission from the surface of black aluminum layers prepared by PVD methods

There is an increasing trend in the utilization of highly nanostructured materials, especially as light absorbers or chemical gas sensors. However, for most applications a more detailed study of surface processes and phenomena is necessary or at least highly beneficial.The present paper describes the surface processes of black aluminum prepared by different PVD methods (magnetron sputtering at room and liquid nitrogen temperature, and thermal evaporation) studied by thermally stimulated exoelectron emission. The actual investigation of the interaction between surface and adsorbed atoms and molecules was carried out after UV irradiation. For the samples prepared in this way, thermostimulated exoelectron emission was measured in the temperature range: liquid nitrogen temperature to 400 °C. SEM analysis revealed significant differences in the morphology of the layers, which were associated with a change in the position of the maxima in the thermostimulated exoelectron emission spectra.The activation energies for the electron emission were calculated. The binding process on the surface of the individual samples and their dependence on the type of black aluminum thin film preparation were described.The results could determine which type of thin film preparation is suitable for use as chemical gas sensors.

Nanocoatings for ballistic applications: A review

Abstract The manufacturing of ballistic impact-resistant (BIR) body armours has evolved over the years with the aim of reducing their weight and enhancing their energy-absorbing capacity upon ballistic impacts. The incorporation of nanoparticles into advanced BIR body armour systems is considered one of the promising techniques. The methods employed in incorporating various nanoparticles in the manufacturing of textile-based body armour systems face a research gap in the optimisation of the associated parameters. This article discusses the mechanism involved in the energy absorption of composites and nanocomposites upon ballistic impact. The current review article highlights the chemical, physical, and mechanical properties of various nanoparticles incorporated into BIR body armour systems. BIR nanocomposites consisting of carbon nanotubes, graphene nanoplatelets, nano-silica, nanoclays, nano-alumina, etc., have been discussed herein. In addition, the significance of various techniques for the dispersion of these nanoparticles was also highlighted. Various methods, such as sol–gel, PVD, CVD, thermal spray, and electroless methods for coating the nanoparticles on the surface of the fibre/fabric were also discussed.

FORMATION AND DECOMPOSITION OF ANOMALOUS SUPERSATURATED MOLYBDENUM SOLUTIONS IN COPPER-BASED CONDENSATES


 Cu-Mo condensates in the concentration range of the latter from 0.3 to 1.5 at.%, obtained by simultaneous evaporation in vacuum with subsequent condensation of the resulting vapor mixture on a non-orienting substrate (PVD method), were studied. The components of this system do not form chemical compounds under equilibrium conditions and are mutually insoluble in liquid and solid states. The structure of Cu-Mo condensates was studied by transmission electron microscopy and X-ray diffractometry both in the derivative state and after a series of isothermal anneals in the temperature range from 300 to 900°C. It was found that small concentrations of molybdenum lead to significant dispersion of the matrix metal. Molybdenum tends to form segregations at the boundaries of copper grains and form a strong coherent bond with the matrix metal, which persists even after isothermal annealing. The conditions for the formation of an anomalous supersaturated solid solution of molybdenum in the copper matrix, as well as the conditions for its decomposition, have been revealed. An assumption is made about the mechanism of formation of such a solution during condensation from the vapor phase, which consists in the kinetic capture of molybdenum atoms by the crystallization front during condensation from the vapor phase. It was found that the decomposition of the supersaturated solid solution begins when heated to 0.5 of the melting point of copper and is accompanied by a dispersion solidification process. During the experiment, it was first recorded that the dispersion solidification process can have a two-stage character. The first peak is observed in the region of 30 minutes of annealing, and the second peak is observed after about 2 hours of isothermal annealing. The height of the dispersion hardening peaks increases with increasing molybdenum concentration. It is suggested that the appearance of the second peak of dispersion hardening is associated with the peculiarities of the interaction between copper grains and molybdenum segregations at the grain boundaries. It is shown that the structure after solution decomposition is typically composite. The advantage of this material over conventional dispersively hardening alloys is the fact that in these pseudo-alloys there is no reverse solution of hardening particles at an increase in temperature.

Kinetics and TD-DFT calculations of base-catalyzed oxidation of acriflavine hydrochloride: Removal of dyes colors from wastewater

The oxidation kinetics of acriflavine hydrochloride (AFH) to nitro-acriflavine (N-AFH) by KMnO4 as oxidizing agent in sodium hydroxide medium at a constant ionic strength of 0.5 moldm−3 was studied using spectrophotometric methods. It was found that the reaction went through two distinct steps that could be monitored. In the first stage, coordination species including transient blue pentavalent manganese and/or green hexavalent manganese species may be made quite quickly followed by the decomposition of intermediates in the second slow stage to produce soluble Mn (IV) and the nitroacriflavine as resulting products of oxidation. It has been investigated how several variables such as pH, ionic strength, permanganate ion concentration, and AFH substrate concentration affect oxidation rates. The experimental results demonstrated a first-order dependence in [MnO4−] and fractional first-order kinetics in each of [AFH] and alkali concentration under pseudo-first-order reaction conditions of [MnO4−] >>10 [AFH]. Sodium hydroxide concentrations accelerated the oxidation reaction, and as the alkali concentration rose, so the type of catalyzed is base-catalyzed. Evidence for the creation of a 1:1 intermediate complex was discovered using spectrophotometry and kinetics. In accordance with the kinetic findings, an efficient oxidation process that is compatible with the kinetic data obtained in terms of the activation parameters evaluated was analyzed, proposed, and debated. There are several techniques used to study the nanostructure thin films (AFH)TF and (N- AFH)TF, with using FT-IR, kinetic, isotherms of liquid-phase adsorption, and optical characteristics. A low deposition rate and a chamber pressure of 5 × 105 mbar are used in the PVD method to create (AFH)TF and (N-AFH)TF thin coatings with a 95 nanometer thickness. The isolated molecules (AFH)Iso and (N-AFH)Iso were additionally optimized using time-dependent density functional theory (TD-DFT) using TD-DFTD/Mol3 and Cambridge Serial Total Energy Bundle (TD-FDT/CASTEP). The optimized geometries, vibrational wavenumbers, intensity of vibrational bands, and various atomic charges of 9VC have all been investigated using DFT-B3LYP system using a 6-31G (d,p) basis set.

Influence of WC-Co knifes pre-treatment with drag finishing method subjected to tool coatings deposition on blunting process

ABSTRACT This paper details the analysis of the micro geometry in modified tools coated with the nano multi-layer TiN/AlTiN obtained by the PVD method. In standard replaceable cutting blades made of WC-Co before deposition, the radius of the blade rounding was increased from about 4 µm to about 13 µm using the drag finishing method with usage of OTEC company device. Next, the tools coated with the multilayer nano-coating TiN/AlTiN were subjected to blunting process. Mentioned above procedure was carried out on a standard 18 mm thick chipboard, assuming the blunting criterion (maximal tool wear on clearance face) Vbmax = 0.2 mm. In addition, previously blunted tools (modified and unmodified) were subjected to a detailed geometric analysis on a contact profilometer. Results show significant differences in the changes of various geometric parameters, in particular in the coefficients determining the asymmetry of the edge roundness denoted with letter K. Especially analysis of changes that concerns coefficient KR based on loss of cutting edge from rake face in comparison to clearance face suggests more intensive abrasive tool wear on rake face. Based on durability tests it can be supposed that changes in values of asymmetry coefficients in general described with letter K can decide about tool life.

Nanoporous structure of vacuum condensates of nickel

The nanoporous structure of nickel vacuum condensates produced by the EB PVD method was investigated. The nanoscale pores were analyzed using small-angle X-ray scattering (SAXS) and scanning electron microscopy (SEM) techniques. It was observed that the set of these nanopores can be considered a bimodal system with characteristic sizes of approximately 1–3 nm and 20–30 nm. It is assumed that the smaller pores form as a result of the coalescence of individual vacancies into clusters during the nickel vapour phase deposition in a vacuum. These pores have a close to a spherical shape and are located inside the grains. After annealing, the characteristics of the nanopore ensemble change: the presence of 1–3 nm pores is almost negligible, while the 20–30 nm pores are partially preserved. Based on this, it is suggested that at elevated temperatures, the 1–3 nm nanopores decompose into individual vacancies, which then migrate towards sinks such as grain boundaries and micropores. This vacancy generation and migration process towards sinks can explain the experimentally observed enhanced diffusion mobility of atoms in vacuum condensates at relatively low annealing temperatures.

Effects of PVD deposition method on electrochemical properties and interfacial contact resistance of CrN coated titanium as PEMFC bipolar plate

ABSTRACT In this research, CrN coating was applied to grade 1 titanium as a bipolar plate for PEMFC. The CrN was deposited by ion beam assisted deposition (IBAD) and the arc ion plating method (AIP). The thickness of the coating layer was about 2.5∼3 μm and it was densely deposited on the titanium substrate. The electrochemical experiments were conducted in an aqueous solution of pH 3 (H2SO4 + 0.1 ppm HF, 80°C) determined by DoE. Hydrogen gas and air were bubbled to simulate the anode and cathode environments, respectively. Various analyses (XRD, EDS, FE-SEM), electrochemical experiments (EIS, potentiodynamic polarisation, potentiostatic experiment), and interfacial contact resistance measurement were performed to evaluate the effects of the PVD deposition method. Due to the difference in the PVD method, CrN and Cr2N were formed in the IBAD specimen, whereas CrN phase was observed in the AIP specimen. The CrN coated specimens presented improved interfacial contact resistance compared to the titanium substrate.

Mechanical and bioactive properties of PVD TiO2 coating modified PEEK for biomedical applications

Polyetheretherketone (PEEK) is gaining popularity in the biomedical field due to its excellent mechanical properties, chemical resistance and biocompatibility. Although PEEK is an excellent biomaterial, it may require bulk surface modification to tailor its properties for specific biomedical applications. In this study, the surface modification of PEEK was achieved by depositing titanium dioxide (TiO2) by PVD method. The microstructure and mechanical properties of TiO2 coatings were studied by SEM/EDS and nanoindentation tests. Conventional scratch tests were performed to determine the adhesion and tribological properties of the TiO2 films. An in vitro study was performed in simulated body fluids to evaluate the osteocompatibility of TiO2 coated PEEK. According to the results The TiO2 coating has a dense microstructure and good adhesion, the critical cohesive load Lc1 is greater than 1N. The TiO2 film improved the mechanical properties of the PEEK substrate: hardness and elastic modulus increased from ∼0.33 to ∼4.03 GPa to ∼3.6 and ∼21.85 GPa, respectively. In addition, compared with the PEEK substrate, the coating showed a 61% improvement in wear resistance and a reduction in the coefficient of friction from 0.38 to 0.09. The results also showed that the TiO2 coating induces the formation of hydroxyapatite on the surface, which promotes the osteocompatibility of PEEK.