Wear Resistance Ability Research Articles

Effect of deposition temperature on the mechanical, corrosive and tribological properties of mullite coatings

Thermal-sprayed ceramic coatings are used worldwide to provide protection from corrosion and wear on components. Nevertheless, they exhibit very poor tribological performance in corrosive conditions, primarily because the high porosity and low cohesive strength, resulting in severe corrosion of metal materials and wear of coatings. Herein, a series of mullite coatings are deposited on the surface of titanium alloys under different deposition temperatures and the splats behavior, mechanical properties, corrosion and wear performance of mullite coatings are studied. Results show that adjusting the deposition temperature can modify the splats behaviors, improve the microstructure and degree of crystallinity and enhance the hardness and cohesive strength. Owing to the improvements, the specimens deposited at higher temperatures have the excellent anti-corrosion and wear-resistant ability.

Laser clad NiCrBSi alloy wear-resistance coating with RE addition on heavy duty spur gear flank

In this research the wear-resistance composite coating successfully produced on heavy duty gear work surface by laser was reported. The coating containing 99 wt.% NiCrBSi alloy and 1 wt.% RE (rare earth element) oxidation powder. The RE addition coupled with laser operating parameters optimization caused elimination of both cracks and pores meanwhile further enhanced comprehensive properties of the laser layer. The coating microhardness, microstructure, phase construction and wear behaviors were tested by hardness tester, SEM equipped with EDS, XRD and tribometer, respectively. The results reflected the fact that the RE addition enhanced the coating ability of wear resistance and laser clad layer properly bonded with the gear flank. The wear volume loss rate of coating was half of that of the gear flank metal the COF curve of coating kept bellow that of the gear flank steel.

Toughness enhancement and tribochemistry of the Nb-Ag-N films actuated by solute Ag

The high-hardness nature of transition metal nitrides (TMN) has been widely exploited for industrial applications ranging from wear-resistance and cutting tools to scratch-resistant films. To design TMN-based films displaying a further improved toughness and a reduced friction represent urgent challenges. Up to now, creating a nanocomposite structure by introducing a very small content of the metal phase has been considered as a common strategy to enhance hardness and toughness. Herein, we present a new approach to incorporate few solute Ag atoms (∼1.5 at.%) into NbN film to form a Nb-Ag-N solid solution structure, achieving enhanced hardness and toughness, coupled with improved wear-resistance ability and remarkable drop in coefficient of friction (CoF). Hardness and toughness enhancement as well as the tribochemistry actuated by solute Ag have been investigated by combined experimental and density functional theory (DFT) analyses. Results show that the hardness enhancement induced by solute Ag stems from the combination of variation in microstructure and increment in bulk modulus B and C44. DFT calculations and electronic structure analyses further reveal that the presence of hybridizations between Ag 5s, 4d orbitals and N p-electrons is responsible for increment in B and C44; furthermore, the appearance of additional Ag eg states contributes to the improved toughness. Additionally, solute Ag can activate self-oxidation by forming Ag2O + Nb2O5 at the surface, which is beneficial for the formation of silver niobate (AgNbO3) during the sliding, thereby triggering the falling of the CoF at only 1.5 at.% Ag. Incorporation of few solute Ag atoms into TMN may provide a new strategy to improve the comprehensive properties including hardness, toughness, friction and wear-resistance.

Chemically robust carbon nanotube – PTFE superhydrophobic thin films with enhanced ability of wear resistance

A chemically robust superhydrophobic nanocomposite thin film with enhanced wear resistance is prepared from a composite comprising polytetrafluoroethylene (PTFE) and carbon nanotubes. The superhydrophobic thin films with hierarchical structure are fabricated by spraying an environmentally friendly aqueous dispersion containing carbon nanotubes and PTFE resin on silicon wafer. Thin films with a contact angle of 154.1°±2° and a sliding angle less than 2° remain superhydrophobic after abrading over 500 times under a pressure of 50g/cm2. The thin film is also extremely stable even under much stress conditions. To further the understanding of the enhancement of wear resistance, we investigated the formation of microsized structure and their effects. The growth of microbumps is caused by attracting solution droplet to the hydrophilic islands on hydrophobic surface.

Comparative physical-tribological properties of anti-friction ion-plasma Ti-C-Mo-S coating on VT6 alloy or 20X13 and 40X steels

Results of comparative tests mechanical and tribological properties of solid antifriction Ti-C-Mo-S coating, deposited by magnetron-plasma combined sputtering method on substrates of VT6 titanium alloy, 40X and 20X13 hardened steels are provided. Coating is sputtered using the same conditions and technological regimes on substrates of different materials. However, the friction tests results showed significant difference in tribological characteristics of coating depending on type of material used for substrate, first of all by wear-resistance ability. Authors suppose that this is due to difference between physical properties such as composition and structure of substrate materials that determines hardness and coating adhesion to surface.

Measuring wear-resistance of AISI 1.7225 steel under various heat treatments: Hydraulic spool valve

Abstract Producing mechanical components with long time functioning is a vital issue in the advanced industries. Wear is one of serious difficulties which prevents from achieving desires. The objective of present study is how wear-resistance of a spool valve, which is an important part of hydraulic valves, can be improved. Hence, different heat treatment methods were implemented to harden the surface layer of this component which is an AISI 1.7225 steel. Wear-resistance measurement test coupled with roughness and distortion tests have been performed to run this analysis. Furthermore, a vision measuring microscope was used to investigate the quality of surfaces that impaired by the wear test. As a result of this work, it was revealed that surface hardening methods generally outperformed the bulk hardening process. In particular, carburizing surface hardening method generates the surfaces with ability of high wear-resistance and better surface quality compared to the other heat treatment processes used in this study. Moreover, highest distortion occurred in the spool valve when gas carburizing heat treatment method has been carried out.

Production Tribological Behavior Feature of Metallic Nanoparticle Additives

Today an application of metal nanoparticles as additives to base oils is widely studied in tribological centers in many countries. The additives containing nanoparticles essentially raise the wear resistance ability of lubricants and reduce the friction coefficient. However, such lubricants are still not widely used. This paper gives a brief analysis of the problem.

Microstructure, wear resistance and cell proliferation ability of in situ synthesized Ti–B coating produced by laser alloying

Abstract Ti–B titanium compound coating with satisfactory wear resistance and good cell proliferation ability was in situ synthesized by a laser alloying technique on a Ti6Al4V substrate. Microstructural analysis indicated that defect-free coating and good interface between the coating and the substrate were obtained. Microstructure and phase structure analysis revealed that the produced coating mainly exhibited dot-like crystals and included α-Ti, TiB, AlTi, AlTi 2 and AlTi 3 , respectively. Microhardness and wear resistance test indicated that the microhardness and the wear resistance were improved greatly by laser alloying treatment in comparison with the substrate. Evaluation of cell proliferation showed that the produced coating was suitable for cell proliferation.

Leverage of cenosphere filler size on mechanical and dry sliding wear peculiarity of polyester composites

This investigation focuses on understanding the effects of submicron size cenosphere fillers on mechanical and wear properties of unsaturated polyester composites. The composites in this study are fabricated with 10 wt.% of 900 nm, 600 nm and 300 nm diameter cenosphere filler particulates. Neat unsaturated polyester composite is also prepared for comparative analysis. The sliding wear test is performed on a pin-on-disc tribometer with the composite pin sliding over a disc comprising hardened ground steel. Friction and wear tests are conducted over a range of sliding velocities (1.57–4.71 m/s), normal loads (10–40 N) and sliding distances (1000–4000 m). In this study, 300 nm size of cenosphere particulate-filled composite shows high wear resistance ability among all fabricated composites. Mechanical properties such as hardness, tensile strength, flexural strength and compressive strength are also investigated. It is observed that mechanical properties of the composites increase with decrease in the particle size. Composites reinforced with 300 nm size of cenosphere particulate shows superior mechanical properties when compared to the other composites in this study. Worn surface morphology of composite specimens has been examined by scanning electron microscopy to understand dominant wear mechanisms.

Anti-wear properties of the molluscan shell Scapharca subcrenata: Influence of surface morphology, structure and organic material on the elementary wear process

As a typical natural biological mineralisation material, molluscan shells have excellent wear-resistance properties that result from the interactions amongst biological coupling elements such as morphology, structure and material. The in-depth study of the wear-resistance performance of shells and the contribution made by each coupling element may help to promote the development of new bionic wear-resistant devices. The objective of this study was to investigate the influence of surface morphology (rib distribution on the shell), structure (rib coupled with nodules) and material (organic matter) on the anti-wear performance of the molluscan Scapharca subcrenata shell. The effect and contribution of each of these biological coupling elements were systematically investigated using the comparative experiment method. All three were found to exert significant effects on the shell's wear-resistance ability, and their individual contributions to that ability were revealed. Organic material can be classified as the principal coupling element, rib morphology as the secondary coupling element and the combined rib-nodule structure as the general coupling element.

Self-assembly and tribological properties of a novel organic–inorganic nanocomposite film on silicon using polydopamine as the adhesion layer

Utilizing the strong coordination interactions between phenolic hydroxyls of polydopamine (Pdop) and silver oxide nanoparticles (Ag2O NPs), Ag2O NPs were successfully assembled on a dual-layer film composed of a polydopamine outer layer and 3-aminopropyltriethoxy silane (APS) sub-layer, on silicon (Si) substrate. The morphologies, structures and chemical compositions of Ag2O NPs and the tri-layer film were confirmed by various instruments, including ultraviolet absorption spectrum (UV), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Furthermore, the micro adhesion forces and macro tribological performances were evaluated using AFM and UMT-2M tribometer (CETR), respectively. The results indicated that the tri-layer film displays favourable friction reduction and wear resistance ability. Hence, this renders the self-assembly attractive for constructing the multilayer-structure films with favourable tribological performances for nano/microelectromechanical systems (NEMS/MEMS).

Tribological properties of self-assembled gold nanoparticles on silicon with polydopamine as the adhesion layer

Adhesion, friction, and wear are the three key problems in moving parts of nano/microelectromechanical system devices. Self-assembly technique has become an important route to solve these problems for its construction of lubricants in micro/nano scales. The present work fabricated a composite dual-layer film of polydopamine/gold nanoparticles on silicon. The morphologies, structures, and chemical constitute of the synthesized nanoparticles and the self-assembled films were confirmed by ultraviolet absorption spectrum, transmission electron microscopy, and atomic force microscopy. To evaluate their micro adhesion forces and macro tribological behaviors of the films, atomic force microscopy and UMT-2M tribometer were employed. The worn surface morphologies of the films and the counterpart steel balls were observed by scanning electron microscopy. The results show that the film has favorable friction reduction and wear resistance ability, which is expected to be applied in nano/microelectromechanical systems.

The Optical Property and Sensitivity of Ag Nanoparticles Deposited Ultra-Thin Diamond-Like Carbon Films

Ag nanoparticles (NPs) had most prominent local surface plasma resonance effect (LSPR) among the all metals. Diamond-like carbon (DLC) film had good biological compatibility, wear resistance, corrosion-resisting and high transmission ability in the visible and near-infrared range. Since the Ag NPs were easily oxidized in air,a new LSPR interface between them and an ultra-thin DLC films was formed by means of a plasma enhanced chemical vapor deposition (PECVD). The morphologies and properties of the Ag NPs deposited ultra-thin DLC films were studied by using Raman spectrometer, X-ray photoelectron spectrometer (XPS) , field emission scanning electron microscope (FESEM) and atomic force microscope (AFM) and so on. And the optical tramsmission sensitivity of the new LSPR interface was also examined. The results indicated that the DLC films deposited in a shorter time had a higher sp3bond content of carbon atoms and more sensitive to refractive index of surrounding media. Moreover, to obtain the optimal morphologies and the sensing property, the deposition time for forming the DLC films should be controlled within 30 seconds.

The Micro-Structure and Wear Behavior of the SiCp/Cu Composites before and after Chemical Plating

In order to improve the interface wettability between the SiCp and Cu materials, the chemical plating and hot pressing sintering technique were utilized to prepare the SiCp/Cu composites. The morphology of the SiC powder before and after chemical plating was studied and the micro-structure of hot-pressed sintered SiCp/Cu composites was investigated in details. The results showed that the finer SiC powder could improve the wear resistance ability of the SiCp/Cu composites obviously. The worn rate reduced with the size of the SiC powder increasing under the same load.

Preparation and Tribological Behaviors of Lubricants—Oil Based on Modified Microbial Oil with Nano-Schiff Base Copper Complex

A W/O microemulsion reactor was used to prepare four kinds of modified lubricants: (i) modified lubricant 1, modified epoxidized microbial oil + rape oil in volume ratio of 1:1; (ii) modified lubricant 2, modified esterified microbial oil + rape oil in volume ratio of 1:3; (iii) modified lubricant 3, modified epoxidized rape oil; and (iv) modified lubricant 4, modified PAO. The individual modified lubricants were further modified with 0%, 0.5%, 1%, and 2% content of nano-Schiff base copper complex (nano-SBCC). A microtribometer was used to evaluate the friction coefficient between ball/flat point contacts immersed in the modified lubricants and operated in reciprocating and linear sliding mode. A comparison of the values of the friction coefficient with the lubricants further modified with nano-SBCC with those of their individual 0% nano-SBCC counterparts indicated significant decrease: (i) almost 19.18% was obtainable for the modified lubricant 1 with 2% of nano-Schiff base copper complex, (ii) almost 16.5% was obtainable for the modified lubricant 2 with 0.5% of nano-Schiff base copper complex; (iii) almost 7.42% was obtainable for the modified lubricant 3 with 1% of nano-SBCC; and (iv) almost 7.01% was obtainable for the modified lubricant 4 with 0.5% of nano-SBCC. These suggested that the addition of nano-Schiff base copper complex can efficiently decrease the friction coefficient of epoxidized or esterified microbial oil. Analyses of two-dimensional images, average profiles (across the mid-section y = 0 of the reciprocating sliding path), and three-dimensional topographies by confocal white light microscope for the worn surfaces of flats immersed in modified lubricant 1 and modified lubricant 2 suggested better wear-resistance of the modified lubricant 2 than that of the modified lubricant 1. The ability of wear resistance for the modified lubricant became better with the increasing content of nano-Schiff base copper complex from 0% to 2%. The study revealed the modification of epoxidized microbial oil + rape oil (1:1 volume ratio) and esterified microbial oil + rape oil (1:3 volume ratio) with Cu(II) chelate of bis(salicylaldehyde)ethylenediamine, reducing the magnitude of friction and wear because of their respective wear self-repairing ability. Such self-repairing ability furnishes the suitability of epoxidized microbial oil or esterified microbial oil to be effectively modified by nano-Schiff base copper complex and to substitute ordinary base oil as a mixture with rape oil.

Tribology Study of Nanodiamond Hybrid Polyurethane/Epoxy Interpenetrating Polymer Networks Materials

Tribology behavior of Nanodiamond(ND) polyurethane(PU)/epoxy(EP) interpenetrating polymer networks hybrid materials were tested by friction wear testing machine. Results showed that when EP content was 30%, resultant PU/EP IPNs exhibited best wear resistance. For ND-PU/EP IPNs hybrids, when the ND addition was 0.2wt%, the best wear resistant ability was obtained. Under dry condition, the effect of wear parameters, such as rotational speed, load and central distance to friction and abrasion value were also investigated.

Strength and Durability of High Performance Road Concrete Containing Ultra-Fine Fly Ash

This paper presents the influence of ultra-fine fly ash on the strength development and durability characteristics of high performance road concrete. The durability of high performance road concrete is investigated including the permeation resistance under hydraulic pressure, the resistance to rapid freezing and thawing, the wear resistant ability and drying shrinkage. Results on compressive strength and strength development of high performance road concrete are also obtained with the main variables being the partial replacements of cement by ultra-fine fly ash of 20%, 30% and 40% by weight of binder material and the binder material of 360kg/m3 and 400 kg/m3. The test results indicate that the use of ultra-fine fly ash as cement replacement leads to a significant improvement of high performance road concrete resistance to permeation and rapid freezing and thawing. The later compressive strength of concrete containing ultra-fine fly ash is also found to be significantly higher than that of control concrete. The wear resistant ability of high performance road concrete is significantly higher than that of control concrete with similar workability. The high performance road concrete also shows the lower drying shrinkage.

The Monitoring Data Analysis of Cover System in Subway Station

Fengtail North Road Station uses a open and cover combination of laying fabricated strap method for the first time, so we monitor the Cover system very closely. We draw schedule curves and analysis the monitoring data for the main component’s monitoring projects of the Cover system. Results show that the deformation values of the components of the Cover system are small, but the values of piles top displacement and settlement are large, at the same time, the lattices of Cover boards have good wear-resistance ability. The conclusion has very great help for optimizing the system design and the promotion of laying fabricated strap method.

Research on Techniques of Electro Less Nickel Plating Nano-C60 Crystals on the Surface of Micromechanical Devices by Laser-Induced Way

In order to improve the dispersion performance of nano-C60 crystals, the surface metallization was achieved by electro less nickel plating; By the laser-induced way, a new composite coating was got on a micromechanical device, which contained some metalized nano-C60 crystals. Research on the fretting friction and wear behavior of the composite coating, its ability of Wear Resistance were improved evidently.

Microstructure and Tribological Properties of Ni-Co/SiC Coatings Prepared by Occlusion Electroplating for Grinding Tools

In order to improve the grinding performance and service life of electroplating composite coatings with high percent of hard abrasives, the composite coatings of Ni-Co/SiC were prepared by occlusion electroplating technology and their microstructure and tribological properties were studied. The research results show that the cathodal electric-current density in occlusion electroplating process and the SiC abrasive size have great influence on microstructure and tribological properties of Ni-Co/SiC coatings. The optimum value of cathodal electric-current density is 1 A/dm2 and the proper SiC abrasive size is about 20 μm, in which the Ni-Co/SiC coatings have excellent wear resistance and high grinding ability. The main wear mechanisms of Ni-Co/SiC coatings are micro-cutting and adhesive wear of matrix alloy, and micro-cracking wear and spalling of SiC abrasives.