Anti-wear Coatings Research Articles

Evaluation of scratch resistance of nitride coatings on Ti grade 2

Hard coatings limiting direct contact of material susceptible to wear are applied in order to improve resistance to abrasive wear. The key importance in using anti-wear coatings has their adhesion to substrate and differences in mechanical properties of the coating and substrate, particularly their Young's module. Studies have analyzed merits of applying nitride coatings TiAlN, AlTiN and hybrid coating TiAlN/TiSiN on titanium substrate ASTM grade 2. For that purpose, nanohardness and scratch tests for each coating were conducted. Apparatus of Anton Paar Company was used in these studies – ultra-high resolution nanoindenter and micro combi tester. Due to the fact, that surface roughness is a significant parameter affecting properties of the surface layer, the first appointed parameters were Sa roughness with a use of optical profilometer Bruker Contour GT. Obtained results suggest the best adhesive grip of hybrid coating TiAlN/TiSiN compared with other tested. The weakest adhesion to titanium grade 2 has TiAlN coating, on which in scratch test has been observed significantly faster total damage, in comparison with other tested. Research results will provide the input data for numerical analysis, enabling fast receiving effects of applying tested coatings without the need to carry out time-consuming research.

PRACTICAL USE OF THE SURFACE LAYERS OF LASER MODIFIED WC-Cu COATINGS

The article presents the study of the effect of laser treatment on the microhardness of WC-Cu coatings applied by electro spark deposition. Observations of friction resistance test results allowed the evaluation of the coatings after laser treatment. The studies were conducted using WC-Cu electrodes, produced by sintering of nanostructural powders. The anti-wear coatings were electro-spark deposited over C45 carbon steel by means of EIL-8A, while the laser processing was performed by electro coats applied using a Nd:YAG, BLS720. Model tests were carried on test mechanical seals for rings made of SiC and WC-Cu coatings before and after laser treatment.

Plasmochemical modification of aluminum-zinc alloys using NH3-Ar atmosphere with anti-wear coatings deposition

This paper constitutes a continuation of studies on modification technologies for 7075 series aluminum alloys (Al-Zn) in plasmochemical conditions using the RF CVD (Radio-Frequency Chemical Vapor Deposition) method. This technique is simultaneously the second stage of alloy ageing. The presented results concern optimization of alloy surface modification using N+ ions (in NH3 or NH3/Ar atmosphere) before obtaining a DLC (Diamond-Like Carbon) layer doped with Si and N.From the results it can be concluded that the most profitable mechanical properties (H, ca. 12 GPa and E, ca. 115 GPa) are obtained when the SiCNH coating process is preceded by Al-Zn alloy surface modification with nitrogen ions. These ions are provided by a flowing NH3 and Ar gas mixture (1:1 ratio). In these process conditions, the lowest tribological wear of the surface is also observed. Furthermore, the obtained coating exhibits a fine-grained structure.

Surface Modification of AISI 440B Stainless Steel and its Influence on Surgical Drill Bits Performance

Abstract The development of modern invasive surgery is highly dependent on the performance of surgical instruments, understood as long-term efficiency arising from high resistance to wear and corrosion. In order to maintain sufficient reliability, surgical cutting instruments are often made of martensitic stainless steels. Nevertheless, the use of ferrous alloys in medical applications is still a concern due to their questionable corrosion and wear resistance. To extend their biocompatibility, improve stability in variable environmental conditions, improve ease of handling, and maximize their performance, diffusion layers and coatings are applied to the surface. The aim of this work was to evaluate the effect of TiN and diamond-like carbon (DLC) surface modification on the performance of surgical drill bits, that is, wear and corrosion resistance, measured in model and field tests. Based on the findings presented, DLC layers can be recommended as anti-wear and anti-corrosion coatings for surgical drill bits.

Cylindrical Magnetron with Dynamic Magnetic Field

The formation of anti-wear coatings on the inner surface of steel cylinders and pipes presents a difficult process-related problem for PA PVD methods. This problem is associated with a strictly limited geometry of the reaction space and dimensions of plasma sputtering-sources. Among the main factors behind physical and chemical phenomena occurring the reaction space, formed within a low-temperature plasma and at its boundaries with a solid object, there are type, concentration, unobstructed path for reacting substances, as well as values and geometry of electrical/magnetic/thermal fields [1-5]. In the research on the plasma-based technology in confined space, the lowest possible distance between the surface being modified and the source of ions of metallic and gaseous elements is taken into account.

Properties of the Electro-Spark Deposited Coatings - Technology and Applications

The paper is concerned with the performance properties of electro-spark deposited coatings, which were determined basing on microstructural and roughness analysis and application tests. The studies were conducted using of the tungsten carbide-ceramic electrodes produced by the powder metallurgy hot pressing route. The anti-wear coatings were electro-spark deposited over C45 carbon steel by means of an EIL-8A. These coatings are likely to be applied to increase the abrasive wear resistance of tools and machine parts.

The Influence of Thickness of Layers in the Multilayer Coating of the PN + AlCrTiN<sub>multinano</sub> Hybrid Layer on Tribological Properties

One of the most perspective directions of the development of surface engineering is related to hybrid technologies. The best-known and widely used hybrid surface treatment technology is a combination of a gas or plasma nitriding process with the process of the deposition of hard antiwear coatings by means of PVD methods. The paper presents the influence of the thickness of layers in the multilayer coating on tribological properties of hybrid layers – PN + AlCrTiNmultinano obtained on the EN X32CrMoV3.3 hot working steel. The research methods concentrated on the analysis of mechanical properties, surface topography and microstructure, and tribological properties. The studies on mechanical properties included tests on hardness using the nanoindentation method and tests on adhesion using the scratchtest. The analysis of surface topography and microstructure was examined by scanning electron microscopy and scanning transmission electron microscopy. The tribological properties were examined using the ball-on-disc method. The coating was tested with alumina balls as counterparts at room temperature. The authors indicate that the PN + AlCrTiNmultinano hybrid layers are characterized by excellent mechanical properties and tribological resistance. In this paper, the authors confirmed that the thickness of layers in a multilayer coating is important in shaping the mechanical and tribological properties of the PN + AlCrTiNmultinano hybrid layer.

Dry Sliding Wear Behaviour of Al 7075 T6 Coated by Plasma Spray Process

-Al7075 T6 alloys are widely used in the aircraft, automotive and die and mold making industry, yet at any time aluminium components should be designed with a third body or in an harsh environment they must be protected with an overlying coating inorder to increase their useful lifespan and improve their surface performance especially in wear and corrosion. The most wide spread technique used to modify the surface properties of Al7075 T6 among them one of the most promosing technology is plasma spraying. It is widely used to manufacture anti-wear and anti-corrosion coatings on to a large class of bulk materials. Extreme performance and high flexibility are the Main characteristic of the coatings achievable by Plasma Spray process. In this work Nickel Carbide + Chromium Composite coating was successfully prepared and deposied with various thicknesses on the Aluminium alloy surface. Nickel Carbide + Chromium composite coating exhibits a significantly increased wear resistance property in the material. The result obtained in this work indicated that the plasma spraying method will be the promising process to coat the composite coating on aluminium based alloy.Keywords: Al 7075 T6, Plasma Spray Process, Nickel Carbide + Chromium

Antiwear coatings for parts that operate under cyclic loading

The outlook for the use of antiwear coatings based on titanium and aluminum nitrides to improve the performance of parts that undergo wear and cyclic loading is considered.

Electrospark Alloying of Carbon Steel with WC-Co-Al<sub>2</sub>O<sub>3</sub>: Deposition Technique and Coating Properties

The paper is concerned with the performance properties of electrospark deposited coatings. The properties were assessed by analyzing the coating microstructure, X-ray diffraction, microhardness, roughness and bonding strength.The studies were conducted using WC-Co-Al2O3electrodes produced by sintering nanostructural powders. The anti-wear coatings were electro-spark deposited over C45 carbon steel by means of an EIL-8A. These coatings are likely to be applied to increase the abrasive wear resistance of tools and machine parts.

添加固体润滑剂h-BN的钛合金激光熔覆γ-Ni基高温耐磨复合涂层研究

添加固体润滑剂h-BN的钛合金激光熔覆γ-Ni基高温耐磨复合涂层研究

添加固体润滑剂h-BN的钛合金激光熔覆γ-Ni基高温耐磨复合涂层研究

添加固体润滑剂h-BN的钛合金激光熔覆γ-Ni基高温耐磨复合涂层研究

WS2含量对钛合金激光熔覆自润滑耐磨复合涂层的影响

WS₂含量对钛合金激光熔覆自润滑耐磨复合涂层的影响

The comparison of antiwear and fatigue properties in higher temperature for PN+CrN and PN+AlCrTiN layer composites

One of the most perspective directions of the development of surface engineering is related to hybrid technologies. The best–known and widely used hybrid surface treatment technology is a combination of gas or plasma nitriding process with the process of deposition of hard antiwear coatings by means of physical vapour deposition (PVD) methods. The paper presents the results of two different wear tests for two different hybrid layers: PN+CrN and PN+AlCrTiN obtained on the EN X32CrMoV3.3 hot working steel. The first one presents results of ball–on–disc tribological tests carried out in the range of temperature, i.e., 25°C and 600°C. The second one presents results of fatigue tests, which indicated the changes of length and density of cracks during the forging process.

Application of finite element method to analysis of tribological properties of aluminum oxide nano-layers

This article describes the research findings achieved by the application of Al2O3 nano-layers coated on aluminum alloys by an electrolytic method. With tribological applications, mainly thin and hard anti-wear coatings were used. Oxide Al2O3 nano-layers created by electrolytic method on aluminum alloys have very good tribological properties when pairing them with plastics and low friction composites. Self-lubricating coatings are a mixture of binding and lubricating agents, which after a putting on sliding surfaces create the coating being characterized by a low friction coefficient that enables a mutual movement of the rubbing areas without the need to apply an extra lubrication media. On the other hand, binding materials – polymers – guarantee the presence of the cohesive force which hold components of the layers together, as well as adhesive forces binding the layer with the base. Practically all polymers can be applied as a matrix for production of polymer composites, but because of excellent friction properties and chemical inertness polytetrafluoroethylene is the most attractive. The structure of the investigated nano-layers was described by the computer image analysis that enables its modeling. Analyzed nano-layers were tribological tested in pair with composites on the basis of polytetrafluoroethylene. In the course of examinations tribological properties were measured that described the quality of sliding pairs, i.e. friction coefficient and abrasive wear. The registered parameters were compared to these measured in other tribological pairs. The differences were analyzed and justified. For predicting stresses and strains generated during the experiment a finite element method was used. The achieved results are similar to the measured real values. Applied computer analysis with finite element method as the calculation method of the cube-plate sliding matching with reciprocating motion and simulation of real forces condition that affect the system, allowed to achieve the following maximal stresses: TG15 (3.02726 MPa), TGK20/5 (3.02732 MPa), TMP12 (4.25076 MPa), and strains: TG15 (0.0045573), TGK20/5 (0.0047507), TMP12 (0.0065434). The stress distributions indicate that the highest values appear in the contact cube-plate area and at the lower cube edges especially in the places being in accordance with the movement direction irrespective of the kind of material used. Material modification results in the change of achieved stresses and strain values according Hooke’s law.

Nanotribological and Wear Properties of Graphene

We prepared few-layer graphene samples by liquid-phase exfoliation in ethanol. By controlling the solvent temperature, sonication time and power, and centrifugation speed and time, we fabricated several-layer graphene from highly oriented pyrolytic graphite (HOPG). The obtained supernatant was added dropwise onto freshly cleaved mica surfaces. Nanotribological study of the samples under high vacuum by atomic force microscope (AFM) showed that frictional force decreased as the number of monolayers (ML) of graphene increased, and their frictional coefficient remained constant when the sample was thicker than about 4 ML. When the coverage reached 7 ML, the frictional coefficient was close to zero. In wear experiments, 2-ML graphene exhibited better wear resistance than the 4-ML sample and had no dependence on directional friction. We also measured the adhesion force of samples containing different numbers of layers of graphene and the mica surface, and found that substrate adhesion is not the main reason for the wear resistance properties of 2-ML graphene. Compared with single-layer graphene, the low friction coefficient of few-layer graphene makes it promising for application in areas such as data storage devices, nanoelectromechanical systems, and anti-wear coatings.

Hybrid surface treatment technology for increase of hot forging dies

Hot working dies are influenced by three main factors causing their destruction: the cyclically changeable mechanical loads, intensive thermal shocks, as well as intensive friction, and erosion. Modification of surface properties with the use of hybrid plasma methods seems to be an effective way of improving its durability. The best known and widely used surface treatment hybrid technology is a combination of the nitriding process with the deposition of hard antiwear coatings by means of PVD methods. The designed composite layer “nitrided layer / Cr-CrN” was obtained with the use of the hybrid technology, which consist of ion nitriding followed by arc-evaporation coating deposition. The maintenance testing was performed on the forging dies employed for production of various parts in the automotive industry. The best durability was obtained for the dies used for the forging of rolling bearing tracks. In comparison with the durability of the dies subjected solely to the gas nitriding, nearly an increase of 600% in the durability was noticed.

Research on Friction and Wear Properties of Plasma Spraying Ni-Base Alloy Coatings on Aluminum Alloy Surfaces

In order to improve the wear resistance and extend service life of aluminum alloy parts, the Ni-base alloy anti-wear coatings were prepared on the surfaces of 7A05 aluminum alloy by plasma spraying technology. The microstructure and interface of the coatings were analyzed, and the friction and wear properties of Ni-base alloy coatings and aluminum alloy substrates were investigated under dry friction condition at room temperature. The research results show that the main phases of Ni-base alloy coating are γ-Ni, CrB and Cr23C6. The thicknesses of diffusion layers existing between intermediate layer and coating, intermediate layer and substrate are respectively 15μm and 20μm. The bonding types of the coating and the substrate are mechanical combination accompanied with partially metallurgical combination. When wore against GCr15 steel balls, the average friction coefficient of the Ni-base alloy coatings is 11.6% lower than that of the aluminum alloy substrates, and the average wear loss of the former is 9.3mg, which is only 1/3 of that of the latter. With the increase of loads, the wear mechanisms of the Ni-base alloy coatings change from slightly micro-cutting wear and fatigue wear to abrasive wear and micro-fracture wear, while those of the aluminum alloy substrates are mainly adhesive wear and abrasive wear as well as slight oxidation wear.

Epoxy Composite Reinforced with Nano and Micro SiC Particles: Curing Kinetics and Mechanical Properties

Epoxy-based composite materials reinforced with hard particles can be used as anti-wear coatings. In this study, a commercial bicomponent resin was used, with 6 and 12% SiC particles in two different particle sizes (nano and 10 µm). The epoxy curing process was studied by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and confocal microscopy. Dynamic mechanical thermal analysis (DMTA) tests evaluated the influence of particle additions on the glass transition temperature (T g ). In addition, mechanical properties (hardness and bending strength) and wear resistance were evaluated. The addition of nanometric particles reduced the reaction order. A higher amount of particles decreased T g due to the lower number of crosslinking points. The agglomeration of nano particles led to non-uniform mechanical properties. 6% nano particle addition dramatically improved wear resistance and decreased the friction coefficient.

Chemical Mechanical Polishing of a Ti-Si-N Nanocomposite and AFM Study on Its Nanostructure

Ti-Si-N films were characterized as a nanocomposite consisting of cubic titanium nitride (TiN) nanocrystallites embedded in an amorphous matrix of silicon nitride (Si3N4). Ti-Si-N films have been used as anti-wear coatings due to their mechanical properties and diffusion barriers for copper metallization in semiconductor processing. The surface of Ti-Si-N is so rough that it is hard to characterize its nanostructure with an atomic force microscope (AFM). Therefore, the Ti-Si-N surface should be polished and smoothened to reduce its roughness before an AFM study. In this study, we investigated a chemical mechanical polishing (CMP) process for preparing Ti-Si-N surfaces for an AFM study on the Ti-Si-N nanostructure by using two different types of CMP slurries. Then a characterization of TiN embedded in a Si3N4 matrix was conducted by using a tapping mode AFM and phase shift imaging.