Wear Resistance Tests Research Articles

Effects of W Alloying on the Lattice Distortion and Wear Behavior of Laser Cladding AlCoCrFeNiWx High-Entropy Alloy Coatings.

Friction and wear properties of hot working die steel at above 800 °C are of particular interest for high temperature applications. Here, novel AlCoCrFeNiWx high-entropy alloy (HEA) coatings have been fabricated on the surface of hot working die steel by laser cladding. The effects of the as-prepared AlCoCrFeNiWx HEA coatings on the microstructure and high temperature friction and wear behavior of hot working die steel are investigated through scanning electron microscopy (SEM), electron probe microanalysis (EPMA), X-ray diffraction (XRD), and X-ray absorption fine structure (XAFS). Having benefited from the formation of W-rich intermetallic compounds after the addition of W elements, the high temperature wear resistance of the coatings is obviously improved, and friction coefficient shows a large fluctuation. The microstructural characteristics of the AlCoCrFeNiWx HEA coatings after the high temperature wear resistance test shows a highly favorable impact on microstructure stability and wear resistance, due to its the strong lattice distortion effect of W element on BCC solid solutions and the second phase strengthening of the W-rich intermetallic compounds. These findings may provide a method to design the high temperature wear resistant coatings.

Влияние химического состава матрицы на структуру и свойства монолитных СВС-композитов

Introduction. The development of new wear-resistant materials obtained by the method of self-propagating high-temperature synthesis (SHS) is an urgent problem in materials science. The SHS method is most widely used in the field of creating new powder materials. Much less attention has been paid to the production of monolithic non-porous composites. For monolithic composites, it is very important to identify the role of the metal matrix and phase transformations in the process of secondary structure formation after the completion of the synthesis process when the obtained material is cooled. The aim of this work was to carry out a comparative analysis of the structure and properties of SHS composites of the Fe-Ti-C-B, Fe-Ni-Ti-C-B, Fe-Ni-Cr-Ti-C-B, and Cu-TiC-B systems. Materials and research methods. Composites were obtained from powder mixtures consisting of thermoreactive components Ti, C, and B, as well as matrix Fe, Fe-Ni, Fe-Ni-Cr, and Cu. The initial powders were thoroughly mixed, loaded into a steel tube container, and the powder mixture was preliminary compacted. Then, the workpieces were heated in an electric furnace to the temperature of the onset of autoignition. After completion of the SHS, the workpieces were deformed with a force of 250 MPa in a hydraulic press at a temperature not lower than 1000 ° C. Samples were cut from the obtained sandwich plates for microstructural studies, density determination, hardness measurements, transverse bending tests and abrasive wear resistance tests. Results and discussion. All investigated composites were characterized by an uneven distribution of strengthening particles TiC and TiB2 over the volume. The use of the Fe-Ni matrix led to the formation of regions with the γ-Fe + Fe2B eutectic structure in the composite and an additional strengthening phase Ni3Ti. The use of Fe-Ni-Cr metal-matrix components led to the formation of two solid solutions in the matrix - austenite and ferrite, and Cr23C6 particles were formed along the boundaries of austenite grains. The maximum transverse bending strength was shown by SHS composites of the Fe-Ti-C-B and Cu-Ti-C-B systems with a matrix of FCC solid solutions. All composites had a hardness of 66 -72 HRC and showed the same abrasion resistance.

Effects of Annealing on the Microstructure and Wear Resistance of Laser Cladding CrFeMoNbTiW High-Entropy Alloy Coating

In this study, a CrFeMoNbTiW high-entropy alloy (HEA) coating was prepared on a Q245R steel (American grade: SA515 Gr60) substrate by means of laser cladding. The effects of annealing temperature on the microstructure and wear resistance of the CrFeMoNbTiW coating were investigated using X-ray diffraction (XRD), a scanning electron microscope (SEM), a Vickers hardness tester and a roller friction wear tester. The results showed that the coating was mainly composed of body-centered cubic (BCC) solid solution and face-centered cubic (FCC) structural (Nb,Ti)C carbides prior to annealing, exhibiting an interdendritic structure and needlelike dendritic crystal structure with average microhardness of 682 HV0.2. The coarsening of the dendrite arms increased gradually after a 10-h long annealing treatment at 800 °C, 900 °C and 1000 °C, and a small amount of Laves phase was produced. After annealing, the highest microhardness value of the as-annealed coating reached 1176 HV0.2, which represents an increase of approximately 72.5% compared to that of the as-deposit coating. The wear resistance testing results imply that this type of coating retains good wear resistance following the annealing treatment and that its wear resistance increases in proportion to the annealing temperature in a range from 800 °C to 1000 °C.

Improved Adhesion of the DLC Coating Using HiPIMS with Positive Pulses and Plasma Immersion Pretreatment

Diamond-like carbon (DLC) coatings are used due to their extraordinary tribomechanical properties, great hardness, high elastic modulus, high wear resistance, low friction coefficient and chemical inertness, which provide them with biocompatibility. Compared to other physical vapor deposition (PVD) coatings of transition nitrides and carbonitrides, DLC has limited adhesion, so it is necessary to develop new techniques to overcome this limitation. This work reports the results of scratch testing for the measurement of adhesion and of tests for wear resistance and nanoindentation in AISI 316L stainless steel coated with a WC:C coating, produced using novel high-power impulse magnetron sputtering (HiPIMS) technology with positive pulses. In addition, the use of a preceding surface modification technique, specifically plasma immersion ion implantation (PIII), was studied with the aim of optimizing the adhesion of the coating. The results show how the coating improved the tribomechanical properties through the use of positive pulse HiPIMS compared to conventional HiPIMS, with an adhesion result that reached critical load values of 48.5 N and a wear coefficient of 3.96 × 10−7 mm3/nm.

TiN-Ag as an antimicrobial and wear resistant coating

Nosocomial infections are a major clinical concern, posing great risks for patients and rising costs for health services providers. This work aims at developing a hard, wear resistant coating, whose antimicrobial properties shall prevent the transmission of infections.TiN coatings deposited by Physical Vapour Deposition, PVD, with different Ag contents have been studied, especially in relation to the hardness and adhesion, their microstructure and morphology. The antimicrobial activity of the surfaces has been assessed against Staphylococcus epidermidis at different time frames, one of the most troublesome source of infections in trauma and orthopaedic surgeries. The electro-tribology properties of different silver contest have been studied. Finally, the coatings have been deposited on surgical acetabular reamers and wear resistance tests have been carried out against synthetic composite bone (simulating cortical and cancellous bone).Results have shown a good coating adhesion on stainless steel (both quantitatively in the scratch tests and qualitatively in the tests against synthetic composite bone), while the hardness decreased with higher Ag percentages. Furthermore, coatings exhibited antimicrobial activity against S.epidermidis, limited silver release, a remarkable wear resistance (vs. uncoated surgical acetabular reamers), while the electrical contact resistance provided valuable information about the evolution of friction and the status of the coating. Therefore TiN-Ag coatings present promising features for reducing the risk of infections, monitoring and extending cutting edge life and quality, and thus limiting damage to living tissues, e.g. necrosis.

Mechanical, Tribological, and Corrosion Properties of Composite NiP-Al2O3 With Different Amount of Particles

Abstract In this study, the influence of Al2O3 particle amounts on the mechanical, tribological, and corrosion properties of the composite NiP-Al2O3 coating was evaluated. AISI 4140 steel was coated with NiP through an autocatalytic bath with the addition of Al2O3 particles maintained in suspension by mechanical stirring. Following, the coated samples were annealed at 600 °C to increase the hardness and to create an interdiffusion layer, which improves coating adhesion and corrosion resistance. The coating surface was characterized by scanning electron microscope (SEM)/energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), microhardness, wear resistance, and corrosion tests. The results showed that the coating particles’ amount depends on the bath agitation speed, the sample orientation during the deposition, and the volume of Al2O3 particles in the bath composition. Also, the number of particles in the coating affects the deposition kinetics and the thickness of the interdiffusion layer, which affects the wear and corrosion resistance.

Tribological Performance of Artificial CoCrMo Prosthesis by ELID Grinding Process

The demand for CoCrMo alloy as an artificial prosthesis has increased for its reliable properties. However, machining of CoCrMo alloy is challenging due to meet the high requirements on prosthesis’ surface quality. In this paper, a new approach of fine ELID grinding on CoCrMo alloy has been proposed using a Kistler three-component dynamometer to monitor the grinding force in real time. This paper also presents the friction and wear performance of CoCrMo alloy. Results show that better efficiency and surface quality can be obtained with low feed speed and small grinding depth. The passivation layer was found on the surface of CoCrMo alloy after ELID grinding, which makes the CoCrMo alloy prosthesis have better biocompatibility. The wear resistance test has proved that CoCrMo alloy has better wear resistance and lower wear quality and is suitable for manufacturing prosthesis.

Modification of Polyhedral Oligomeric Silsesquioxane (Epoxy Resin-Polyhedral Oligomeric Silsesquioxane) by Inorganic Nanoparticles

As a kind of green and clean energy, solar energy has attracted more and more attention. Among them, the antifouling treatment on the surface of photovoltaic panels is the key to improve the photoelectric conversion efficiency. EP-POSS (epoxy resin-polyhedral oligomeric silsesquioxane) has good hydrophobicity and has potential application value in the field of protective coating of photovoltaic panels. UV-vis tests show EP-POSS light transmittance about 85%, have good pervious to light quality, through the ZnO and SiO2 inorganic nanoparticles to modification of EP-POSS, in order to improve the wearability of EP-POSS coating and bacteriostasis, the EP-POSS microstructure was tested by TEM, XRD characterization of nano particles and the compatibility of EP-POSS, again with TGA, adhesion and wear resistance test the performance of the EP-POSS found inorganic nanoparticles can better improve the use performance of EP-POSS.

Influence of processed waste bagasse fibre-stone dust-6063 aluminium alloy particle on the characteristics of hybrid reinforced recycled HDPE composites

ABSTRACT A novel hybrid composite material was developed through the compression moulding technique by adding bagasse fibre, stone-dust and 6063 aluminium alloy (Al-Mg-Si) particles to recycled high-density polyethylene (rHDPE) matrix. The bagasse fibres were treated while the stone-dust and 6063 aluminium alloy (Al-Mg-Si) particles were sieved to particle sizes of ˂75 µm and ˂250 µm, respectively, before blending with the matrix. The work investigates comparatively, the influence of bagasse fibre-stone dust (hybrid-of-2) and bagasse fibre-stone dust-Al-Mg-Si particles (hybrid-of-3) on composite formation systems for reinforced rHDPE composites. The properties of recycled HDPE and rHDPE composites were thoroughly investigated through selected mechanical properties, wear resistance and thermal conductivity tests. The results show that the addition of bagasse fibre-stone dust-Al-Mg-Si alloy particles improves the mechanical, wear and thermal properties of the composites. The ultimate tensile strength was enhanced by 39% having a UTS value of 32 MPa, tensile modulus by 13% with a value of 98 MPa and wear resistance by 53% with a value of 0.8 g. SEM images showed that these reinforcements blended more properly when lower contents were added. This is responsible for the enhancement observed in the mechanical properties of the hybrid-of-3 reinforced composite.

Manufacturing and Characterization of Functionally Graded Material Automotive Piston Using Centrifugal Casting Technique

The process of fabricating reliable materials according to efficient usage has become one of the most vital concerns. In this paper, the fabrication of functionally graded materials (FGMs) is the target using a specified application of an internal combustion engine piston model to achieve such a gradient. With a convenient rotational speed under the concept of centrifugal casting technique, the required gradient piston was successfully produced from two pure aluminum alloys A336 and A242 by such a new mechanical technique for having the required gradient. The percentages of internal ingredients, mainly, silicon were controlled axially through the piston. Chemical composition analysis, micro-hardness and wear resistance tests were performed to check the gradient and to know the difference between mechanical properties for each piston portion from its top combustion chamber to its skirt, achieving compatible results through performed tests. Obvious opposite direction gradient of silicon content to copper content appeared. Micro-hardness, wear resistance and coefficient of friction values showed a successfully gradient in the axial direction of the piston model.

Tunable Superhydrophobicity from 3D Hierarchically Nano‐Wrinkled Micro‐Pyramidal Architectures

AbstractInterfacial surfaces with hierarchical structures have triggered intense research interest and been used in a broad range of applications ranging from anti‐icing, anti‐fogging, surface‐enhanced Raman spectroscopy to catalytic reaction. However, the high‐cost manufacturing processes and the limited durability remain as great challenges that need to be addressed, especially for superhydrophobicity. In this work, a novel hybrid approach for stretchable, transparent, and robust superhydrophobic surfaces is proposed, constructing micro‐pyramid architectures with tunable hierarchical wrinkles efficiently and in an environmentally friendly manner. Due to the multiscale structures, excellent superhydrophobicity is obtained with contact angle of ≈172° and sliding angle ≈5° in a steady “Lotus” state. Further, the wear resistance and stability tests also suggest a superior performance under simulated severe real‐world applications. Utilizing such multiscale synergistic co‐operation effects can be an excellent manufacturing strategy and be extended to other surface engineering where hierarchical architectures are needed.

The Effect of Graphene Nanofiller on the Surface Structure and Performance of Epoxy Resin-Polyhedral Oligomeric Silsesquioxane (EP-POSS).

Epoxy resin–polyhedral oligomeric silsesquioxane (EP-POSS) has excellent mechanical properties and hydrophobic properties. In order to adapt for application in sensor and photovoltaic fields, graphene, nano-SiO2 and nano-ZnO were used to modify EP-POSS. FTIR was used to characterize changes on the surface structure after introducing nanoparticles. The change of hydrophobicity was measured using a contact angle test. TEM test results showed that nanoparticles were successfully inserted between the graphene sheets. However, the content of Si on the surface was low, as the cage structure of POSS in the molecular chain was coated by epoxy groups. XRD tests indicated that nanoparticles facilitated the dispersion of graphene in EP-POSS. XPS characterized the chemical state and content of the elements, confirming that the addition of graphene can induce the enrichment of Si on the surface of EP-POSS, which had a shielding effect on the main chain and improved the hydrophobicity. Wear resistance and adhesion tests showed that, after the introduction of nanoparticles, the EP-POSS coating film met the requirements of graphene materials.

Characteristics of wood powder, coconut fiber and green mussel shell composite for motorcycle centrifugal clutch pads

This research is motivated by the need for environmentally friendly motorcycle centrifugal clutch pads. Utilization composites of wood powder, coconut fiber, and green mussel shells for centrifugal clutch pads have not been much discussed in the research. Centrifugal clutch functions to transmit power from the engine to the drive train with a centrifugal force mechanism. This study aims to determine the characteristics of the hardness, wear, coefficient of friction, and microstructure of the composite. Composite material was made with three variations, namely specimen 1 consisting of 20% wood powder, 20% coconut fiber, 60% resin, and 0% shells. Specimen 2 made of 20% wood powder, 20% coconut fiber, 50% resin, and 10% shells. Specimen 3 is made from 20% wood powder, 20% coconut fiber, 40% resin, and 20% shells. All specimens were characterized by hardness testing according to ASTM E92 by the Vickers FV-300e. Each specimen was tested three times and the average data was taken. Wear resistance testing according to ASTM G99 by OGOSHI machine. Friction coefficient testing is based on the principle of friction in the inclined plane. While microstructure testing uses SEM by JEOL JSM-6510LA. The results shows that the composition of wood powder, coconut fiber, and shell influenced the test results. Specimen 3 shows the highest value of hardness, wear and coefficient of friction compared to others so that it can be used for the centrifugal clutch.

Design, Development and Preparation of Pouched Scuba-Knitting Spaced Fabric

Objective To improve the protection of human joints and avoid the injury caused by falls in the elderly. By testing and evaluating the wearability and mechanical properties of the pouched scuba-knitting fabric with no filling material, filled with EPS and POM, this paper provides a theoretical basis for the development of the protection products for the elderly. Methodology Using nylon filament and spandex stretch yarn as raw materials, two kinds of cushioning materials, EPS and POM, are respectively filled into pouched scuba-knitting weft-knitted structure. Results Due to the limit of 3mm spacing between front and rear needle beds of the computerized flat knitting machine, among all kinds of samples tested, the air permeability of EPS is stronger than that of POM with the increase of EPS sphere diameter. Because EPS spheres are more easily attached to water, the moisture permeability is shown to be the best. The mass loss of non-filled fabric is the greatest in the wear resistance test. Due to the characteristics of weft-knitted fabrics, there is no obvious difference among the three kinds of knitted fabrics in the tests of bursting, stretch recovery, pilling. Conclusion The pouched scuba-knitting structure filled with EPS is more suitable for the design and production of the protective fabric for the elderly afterwards.

Improvement of Microstructure and Wear resistance of X12 Tool Steel by Using Laser Surface Re-Melting Technique

Nd-YAG lasers have been successfully used in recent years as reliable heat source to surface modification of engineering materials such as laser surface re-melting. In the present study, X12 tool steel was surface modified by using pulse Nd-YAG laser technique. Laser parameters are selected of 12 J pulse energy, 15 Hz frequency, 20 mm defocus length, 6 ms pulse duration, and 5.6 mm /s mm scanning speed. These parameters were chosen after undertaking trials to give suitable parameters in this process. Optical microscopy and backscattered scanning electron microscopy (SEM) with EDS and X-ray diffraction techniques were used to analyse the microstructure changes of the surface of tool steel. Wear resistance test was achieved by using a pin on disk method. The reason for this work is to improve the wear resistance for surface layer of tool steel after changes the morphology of the structure by rapid solidification during laser re-melting. In general, the structure consists of the dendrite and cellular structures with δ ferrite formed under conditions of rapid solidification without the primary coarse carbides. After laser melting, the results of the structure at the surface layers show an increase in wear resistance.

A comparative study of mechanical properties and corrosion behavior of fusion-bonded epoxy and liquid epoxy coatings and their service life in drill pipe applications

The current investigation evaluated the service life and characteristics of fusion-bonded epoxy (FBE) and liquid epoxy coatings applied on ST37 substrates to determine the optimal properties for the inner coatings of the drill pipes in the practical operating conditions. For this purpose, various mechanical tests of flexibility, hardness, adhesion resistance, impact resistance, and wear resistance along with corrosion tests of salt spray, acid immersion, and impedance tests were employed. The mechanical test results verified that FBE coating with 88 Shore D hardness and 25 MPa adhesion strength had the lowest weight loss during the wear test and provided the most desirable mechanical properties among the liquid coatings. Furthermore, the FBE sample was found to have the maximum flexibility and the highest impact resistance. The corrosion test results revealed that the FBE sample had the lowest corrosion rate, which can offer extended durability for the internal coating of the drill pipes. The results also showed that the higher compactness of the FBE coating structure, as well as the lower permeability against the penetration of aggressive agents, were the primary factors accountable for the superior service life.

Investigations into the tribological properties of Titanium-dioxide alumina coated mild steel

Temperature and load are the two factors that have an influence over the way friction affects interacting material surfaces that are in relative motion. Surface interactions under higher temperatures result in accelerated wear rate and will result in a reduction of the overall life cycle of a mechanical part. Applying a suitable coating on these interactive surfaces could considerably improve the wear resistance of any material. In this study, mild steel specimens were coated with titanium dioxide alumina using the plasma arc spraying method. The tribological properties of titanium dioxide alumina coated mild steel specimens were investigated using various experiments like the wear resistance test and hardness test. A reciprocating wear testing machine was used to study the wear resistance of the coated mild steel specimens. During the wear test, coated mild steel specimens were subjected to different load conditions and temperatures. The tool with a bearing ball on the tip was slid on the sample surface and it was observed that the coefficient of friction is related to working temperature. Scanning Electron Microscope and Energy-dispersive X-ray spectroscopy (EDS) revealed that the coating is intact even after conducting the rigorous wear test which confirms that the coating material has imparted good wear resistance to the specimens. From the results of the hardness test, it is evident that the hardness of the surface also influences the rate of wear.

Increasing the durability of the parts of tillage machines due to replaceable wear-resistant elements

Annotation Purpose. Increasing the durability of the parts of tillage machines due to the use of replaceable wear-resistant elements in their design. Methods. Abstract-logical, monographic, computational-constructive, graphic, micrometer, mathematical and physical modeling, experiment planning, mathematical statistics and regression analysis of experimental data, comparative and field tests of locally hardened experimental parts of tillage machines using the main provisions of the theory of friction and wear in abrasive environment. Results. A process of hardening with replaceable wear-resistant elements of ЧГ-40 subsoiler bits and a group process of hardening with replaceable wear-resistant elements of cutting knives (left and right) ЧГ-40 subsoiler points has been developed. Conclusions 1. A list of materials has been determined that are recommended for the manufacture of wear-resistant replaceable elements of the parts of soil cultivation machines, in particular, based on the results of accelerated comparative tests for the abrasive wear resistance of samples of different materials for replaceable elements, tungsten plates ВК-13 are recommended. 2. The processes of hardening with replaceable wear-resistant elements of chisels and cutting knives of the ЧГ-40 subsoiler points have been developed, which are based on hardening by the soldering method of tungsten plates ВК-13. 3. Based on the results of the production check of technological processes in the conditions at the Agricultural Limited Liability Company “Agrofirma “Krasne”, it was established that the operating time of the experimental working bodies of tillage machines exceeds the operating time of the serial chisel-subsoiler ЧГ-40 paws by more than 3 times. Keywords: durability, replaceable elements, hardening, wear resistance, soldering, parts, processes.

РАЗРАБОТКА ФУНКЦИОНАЛЬНЫХ ИОННО-ПЛАЗМЕННЫХ ПОКРЫТИЙ НА ОСНОВЕ МНОГОСЛОЙНЫХ ГЕТЕРОГЕННЫХ СТРУКТУР НИТРИДОВ МЕТАЛЛОВ

The article deals with the development of ion-plasma coating systems based on multilayer heterogeneous structures of the type (Me1)N/(Me2)N, (Me1–Me2)N/(Me3)N, (Me1–Me2–Me3)N/(Me4)N, where Me: Ti, Al, Cr, Mo. Tests for heat resistance and wear resistance, gas-abrasive resistance, metallographic and x-ray structural studies were carried out. It is shown that the ion-plasma coating (Ti–Al–Cr)N/CrN can be used to increase the heat resistance, wear resistance (including abrasive) of steel and titanium intermetallic parts of aircraft gas turbine engines operating in the temperature range up to 800 °C.

STUDY ON FRICTION AND WEAR PROPERTIES OF HARVESTING BLADE BASED ON TiC/FeCoNiCuTi HIGH ENTROPY ALLOY MATRIX COMPOSITE

FeCoNiCuTi high entropy alloy (HEA) and TiC/FeCoNiCuTi high entropy alloy matrix composites were prepared by induction electromagnetic melting. The microstructure and composition of the composites were identified by XRD, SEM and EDS. The results show that the composite is FCC crystal form, and square TiC particles are dispersed on the matrix. The wear rate and friction coefficient of the composites were tested by wear resistance testing machine. The effects of friction speed and load on the wear properties of the composites were discussed and the wear mechanism was analyzed. When the load is 200N and the sliding speed increases from 0.2m/s to 0.4m/s, the wear rate of the matrix increases, the wear rate of the composite increases first and then decreases, and the value of the friction coefficient decreases. When the sliding speed is 0.3m/s and the load increases from 100N to 200N, the wear rate of the matrix and the composite increases and the friction coefficient decreases. The wear mechanism is combined wear, with abrasive wear as the main wear at high load and oxidation wear as the main wear at high sliding speed.