Purpose This study aims to investigate the effect of MoS2 powder on tribological properties of sliding interfaces. Design/methodology/approach Loose MoS2 powder was introduced in the gap of point-contact friction pairs, and sliding friction test was conducted using a testing machine. Friction noise, wear mark appearance, microstructure and wear debris were characterized with a noise tester, white-light

Purpose The purpose of this paper is to use a combination of numerical simulation and experiment to evaluate the performance of laser surface texturing (LST) in the field of gear lubrication, and to more accurately predict the lubrication characteristics of different surfaces. Design/methodology/approach The method used in this paper is developed on the basis of the deterministic solution of the three-dimensional

Purpose The purpose of this study is to reduce the use of Zinc dialkyl dithiophosphates (ZDDP) and improve the frictional properties and thermal oxidation stability of Perfluoropolyether (PFPE) grease by adding antioxidant additives. The addition of antioxidants can reduce the consumption of ZDDP as an antioxidant, thus improving the anti-wear efficiency of ZDDP and reducing the excess phosphorus element

Purpose The mechanical and tribological properties of polymers and polymer composites vary with different environmental conditions. This paper aims to review the influence of humidity/water conditions on various polymers and polymer composites' mechanical properties and tribological behaviors. Design/methodology/approach The influence of humidity and water absorption on mechanical and tribological

Purpose This paper aims to study the lubrication and sealing performance on the textured piston pair under the cross action of the shape and structure parameters. This paper further carries out the optimization design of low energy consumption hydraulic impact piston pair. Design/methodology/approach Based on the characteristics of the ring gap seal piston pair, the flow field analysis model of the

Purpose Aviation field requires a material with greater tribological characteristics to withstand the critical climate conditions. Hence, it is of paramount importance to enhance the wear resistance of material. AZ91D magnesium alloy is a light weight material used in the aviation field for the construction work. The purpose of this study is to augment the wear properties of AZ91D alloy by reinforcing

Purpose Under-race lubrication can increase the amount of lubricating oil entering a bearing and greatly improve lubrication and cooling effects. The oil-air two-phase flow and heat transfer characteristics inside a ball bearing with under-race lubrication play a key role in lubrication and cooling performance. The purpose of this paper is to study these two characteristics, and then provide guidance

Purpose This paper aims to develop a Mini-Tribometer for in-situ observation of subsurface. Design/methodology/approach To observe the change of the microstructure during wear in real time, an in-situ observation mini-tribometer was developed according to the requirements of the basic frictional experiments and carried out the verification experiments. Findings The subsurface images and the tribological

Purpose The purpose of this study is to investigate the effects of load and rotation speed on dry sliding of silicon nitride, including a series of tribological behaviors (friction coefficient, wear rate, temperature rise, etc.) and wear mechanism. Through the analysis of the above characteristics, the influence law of load and speed on them and the internal relationship between them are determined

Purpose This study aims to the preparation and tribological characteristics of graphene/triangular copper nanoplate composites (abbreviated as GN/Cu nanoplates) as grease additive and clarifies the growth mechanism and tribological mechanism of GN/Cu nanoplates by different analysis methods. In this paper, it is expected to alleviate the problems of easy aggregation and poor dispersion stability of

Purpose Dissimilar materials found applications in the structural fields to withstand the different types of loads and provide multi-facet properties to the final structure. Aluminum alloy materials are mostly used in aerospace and marine industries to provide better strength and safeguard the material from severe environmental conditions. The purpose of this study is to develop new material with superior

Purpose This paper aims to describe how successfully a particular restrictor delivers its best in increasing the conical journal bearing performance. The restrictors are used in the hole-entry conical journal bearing subjected to hybrid mode. Thus, the restrictors, like constant flow valve (CFV), orifice and capillary, are studied comparatively. Design/methodology/approach Numerical simulation for

Purpose This paper aims to study the effectiveness of using thermal spray (TS) coated bores in reducing friction under the mixed lubrication (ML) and elastohydrodynamic lubrication (EHL) regimes. Design/methodology/approach A reciprocating tribometer with a stroke length of 100 mm, was built to measure the coefficient of friction (COF) at the mid-stroke and ring reversal positions and to conduct sliding

Purpose The purpose of this study is to investigate the influence mechanism of different interface component surface textures on the ultrasonic motor (USM) output performance. Design/methodology/approach The energy transmission mechanism of the traveling-wave ultrasonic motor 60 (TRUM-60) was numerically and experimentally investigated by fabricating dimple textures with different feature types on

Purpose The purpose of this paper is to study the film-forming capacity of logarithmic crowned roller for tapered roller bearing (TRB) and to design a tapered roller profile based on an elastohydrodynamic lubrication model. Design/methodology/approach A coupled model, incorporating a quasi-static model of TRBs and an elastohydrodynamic lubrication model was developed to investigate the load distribution

Purpose The purpose of this study is to fabricate high-aspect-ratio grooves with high surface quality by femtosecond laser (FS) to improve the machinability of silicon carbide (SiC) and optimize the process parameters in micromechanical applications. Design/methodology/approach Four contrast experiments are reported to characterize the FS laser grooving process for SiC with polarization direction,

Purpose The purpose of this paper is to investigate the influence of binder effect on tribological behavior of brake friction composite materials: a case study of phenolic resin modified by N-Methylaniline. Design/methodology/approach Four different friction materials have been fabricated by varying modified phenolic resin content. The samples were prepared by the conventional powder metallurgy methods

Purpose This study aims to deal with development and performance analysis of high-velocity oxy-fuel (HVOF) thermally sprayed Mo2C-based WC-CoCr (tungsten carbine cobalt chrome) (Co-10% and Cr-4%) cermet coating deposited on the pump impeller steel 316 L. Design/methodology/approach In this work, a study was carried out by modifying the conventional WC-CoCr powder with a small addition of molybdenum

Purpose The purpose of this paper is to study the influence of surface precision on the lubrication state of the roller chain under adequate and rare oil supply conditions, respectively. Design/methodology/approach The straightness error and roughness error of the pin generatrices were measured and the influence of surface precision on the lubrication behavior under steady state and reciprocating motion

Purpose The purpose of this paper is to study the dynamic features of friction coefficient during running-in state based on recurrence analysis, so as to recognize the running-in state of crankshaft journal bearings. Design/methodology/approach The friction coefficient was measured in the friction experiments and the dynamic features are analyzed by recurrence plots (RPs), unthreshold recurrence plots

Purpose The purpose of this paper is to study the flow field characteristics of the micro-scale textured bearing surfaces using the lattice Boltzmann method based on the microscopic dynamics of the fluid. Design/methodology/approach Considering the inertia effects and the micro-scale effects, the models of a single micro-scale texture unit cell with different shapes and different film thickness ratios

Purpose The purpose of this paper is to carry out erosion wear investigation on high-velocity oxy-fuel (HVOF)-deposited 86WC-10Co4Cr and synergistic Ni/Chromia powder (i.e. 80Ni-20Cr2O3) on AISI 316L. Design/methodology/approach Design of experiments-artificial neural network (DOE-ANN) methodology was adopted to calculate the erosion wear. Taguchi’s orthogonal array L16 (42) was used to perform set-of-erosion

Purpose The purpose of this paper is to improve the tribological properties of aluminum cylinder liner. Higher martensite contents were closely related to the higher hardness and excellent wear resistance of Fe-based coatings. Furthermore, the grain size of the Fe-based coating was approximately 40 nm, which provides an excellent fine grain strengthening effect. Design/methodology/approach To improve

Purpose This study aims to produce lubricating surfaces with micro-channels by the selective laser melting (SLM) method, and to investigate their tribological behavior. Design/methodology/approach In this study, three kinds of samples with different geometries were designed, impregnated with oil and then subjected to flow analysis in a virtual environment using Ansys Fluent software. According to the

Purpose This paper aims to research the effect of the different structures of dimpled textures on the rod bearing surfaces on improving the engine’s lubrication efficiency and friction power loss (LE-FPL). Design/methodology/approach Based on the hydrodynamic model of the rod bearing, the effect of different structures of dimpled surfaces including circular dimples (CD), square dimples (SD), wedge-shaped

Purpose The purpose of this study is to investigate the influence of dimple radius, depth and density on the lubrication performance of the plunger. Design/methodology/approach A lubrication model was adopted to consider eccentricity and deformation during the working process of the plunger, and a rig test was performed to confirm the simulation results. The texture was fabricated using laser surface

Purpose In this study, the dynamic characteristics of the water-lubricated rubber bearing considering asperity contact are numerically studied, including water-film stiffness and damping coefficients and plastic-elastic contact stiffness coefficient. Design/methodology/approach The Kogut-Etsion elastic-plastic contact model is applied to calculate the contact stiffness coefficient at the bearing-bush

Purpose The purpose of this paper is to elucidate the tribology behavior of polytetrafluoroethylene (PTFE) incorporated with three types of nickel–phosphorus (Ni-P) particles (i.e. low phosphorus [LP], medium phosphorus [MP] and high phosphorus [HP]) under dry sliding condition. Design/methodology/approach Ni-HP, Ni-MP and Ni-LP particles fabricated via an electroless plating process were incorporated

Purpose Under the influence of loading, manufacturing, installation and other factors, the axis of sleeve bearing and journal will not be aligned, which will have a great impact on running stability and life of bearing. The existence of oil groove can effectively improve the life of sleeve bearing and working efficiency. The lubrication performance of two and three grooves sleeve bearing considering

Purpose The purpose of this study is to present a novel approach for the evaluation of tribological properties of brake friction materials (BFM). Design/methodology/approach In this study, a BFM was newly formulated with 16 different ingredients and produced using an industrial hot compression molding process. Experimentation was carried out on the brake tester, which was developed for this purpose

Purpose The purpose of this paper is to analyze the mechanism of particle erosion in butterfly valve pipelines under hydraulic transportation conditions. The results will affect the sealing and safety of butterfly valve pipelines and hopefully serve as reference for the anti-erosion design of butterfly valve pipelines. Design/methodology/approach Through the discrete element method (DEM) simulation

Purpose This study aims to scrutinise the impact of fibre length and its composition on the tribological attributes of oil palm fibre (OPF) polymeric composite as an alternative brake friction material. Design/methodology/approach Fabrication of the sample was conducted by using a hot-compression method. The tribological test was carried out by deploying a ball-on-disk tribometer. Analysis of the data

Purpose This paper aims to address the coating and compound analysis of diamond-like carbon (DLC) on steel, to understand the frictional behavior in tribological gear systems presented in paper Part I. Here, the Ti and Zr modified DLC coating architectures are analyzed regarding their chemical, mechanical and thermophysical properties. The results represent a systematic analysis of the thermal insulating

Purpose The aviation field requires a material with the ability to withstand severe environmental conditions. The purpose of this paper is to provide higher wear resistance and improve the lifetime of aircraft. Hence, it is vital to enhance the wear resistance and strength of the material. Design/methodology/approach In this investigation, the Az91D magnesium alloy was reinforced with lanthanum (La2O3)

Purpose The most promising replacements for the industrial applications are particle reinforced metal matrix composites because of their good and combined mechanical properties. Currently, the need of matrix materials for industrial applications is widely satisfied by aluminium alloys. The purpose of this paper is to evaluate the tribological behaviour of the zinc oxide (ZnO) particles reinforced AA6061

Purpose The purpose of this study is to develop a normal contact stiffness (NCS) model among three disks of the assembled rotor system, which systematically considers the friction coefficient, the asperities interaction and the elastoplastic contact regime. Design/methodology/approach Based on the revised fractal theory, considering the friction effect, the elastoplastic contact regime and the asperities

Purpose This paper aims to present the mixed elastohydrodynamic lubrication (EHL) model and obtain the leakage characteristics for the skeleton reciprocating oil seal. Design/methodology/approach The model consists of a finite element analysis of the contact pressure, a fluid mechanics analysis of the fluid film, a contact analysis of the asperity contact pressure, a deformation analysis of the seal

Purpose The presence of ferrous wear debris in lubricating oil may cause progressive damage in the internal combustion engines. Online monitoring of the size and concentration of these particles in the oil is a way to optimize the engine performance and its life cycle. Design/methodology/approach In this study, an online sensor was designed and fabricated to identify ferrous wear particles in the engine

Purpose The last stage of the cold rolling process is skin-pass rolling and one of its most significant goals is to obtain appropriate topography on the surface of the sheet steel used extensively such as in automotive industry. The purpose of this paper is to investigate the effect of thickness change and various reduction ratios on roughness transfer of DC04 grade sheet material. Design/methodology/approach

Purpose This research aims to present the characteristics of dimple structure which was fabricated using a turning machine, where the characteristics include sizes, shapes, area ratio and aspect ratio. This research aims at filling the gap in the machining parameters of previous research in producing dimple by using turning process with the aid of dynamic assisted tooling for turning (DATT). In producing

Purpose The purpose of this paper is to understand the effect of particle content, applied load and sliding speed on the tribological properties of A356-SiCP composites manufactured using a newly developed vacuum stir casting technique. Design/methodology/approach A356 alloy reinforced with 10, 15 and 20 vol% SiC particles was prepared by vacuum stir casting. Tribological tests were carried out on

Purpose This paper aims to elucidate the effects of lubricant groove shape, vertical load, swing angle and grease injection cycle on the friction and wear performances of journal bearings under the grease lubrication condition. Design/methodology/approach Three different types of lubricant grooves, namely, numeral eight-shaped, axial straight line-shaped and circular blind hole-shaped, were designed

Purpose This paper aims to improve the tribological performance of grease-lubricated spherical plain bearings (SPBs) under heavy load, dimple-type textures were prepared by laser on the outer surface of the inner ring. The influence of roughness parameters of a textured surface on reducing friction coefficient and temperature rise was also explored. Design/methodology/approach This study adopts a laser

Purpose The purpose of this paper is to investigate the fretting wear performance of ultra-high-molecular-weight-polyethene (UHMWPE) with addition of GO and SiO2. Design/methodology/approach In this study, GO were synthesized and SiO2 nanoparticles were grafted onto GO. The effect of nanofiller on fretting wear performance of UHMWPE was investigated. Findings The results indicated that GO was successfully

Purpose The purpose of this paper is to study the behavior of a single ridge passing through elastohydrodynamic lubrication of point contacts problem for different ridge shapes and sizes, including flat-top, triangular and cosine wave pattern to get an optimal ridge profile. Design/methodology/approach The time-dependent Reynolds’ equation is solved using Newton–Raphson technique. Several shapes of

Purpose This paper aims to develop of magnetic field controlled friction braking technology, a novel brake friction material with magnetic was designed and prepared in this paper. Design/methodology/approach The permalloy, a soft magnetic material, was selected as an additive to design and prepare the magnetic brake material. The friction, wear performance and permeability of each brake pads were investigated

Purpose The purpose of this paper is to improve static/dynamic characteristics of active-controlled hydrostatic journal bearing by using fractional order control techniques and optimizing algorithms. Design/methodology/approach Active lubrication has ability to overcome the unpredictable harsh environmental conditions which often lead to failure of capillary controlled traditional hydrostatic journal

Purpose This study aims to investigate the influence of geometry of bush-pin pair from a perspective of optimal lubrication through a thermal elastohydrodynamic lubrication model for finite line contact. Design/methodology/approach A constitutive equation: Ree-Eyring fluid is used in the calculations. The real chain sizes, i.e. equivalent radius of curvature, bush length, length of the rounded corner

Purpose The purpose of this paper is to enhance sealing and rotordynamic performance of hole-pattern damping seal (HPDS) and labyrinth seal (LS) by structural innovation and geometrical optimization of special-shaped hole or annular-groove cavity. Design/methodology/approach The unsteady flow was transformed into steady one using moving reference frame method. The full period numerical models of LS

Purpose The purpose of this paper is to acquire sealing properties of supercritical CO2 (S-CO2) T-groove seal under ultra-high-speed conditions by thermo-elastohydrodynamic lubrication (TEHL) analysis. Design/methodology/approach Considering the choked flow effect, the finite difference method is applied to solve the gas state equation, Reynolds equation and energy equation. The temperature, pressure

Purpose The purpose of this study is to achieve an accurate intelligent fault diagnosis of rolling bearing. Design/methodology/approach To extract deep features of the original vibration signal and improve the generalization ability and robustness of the fault diagnosis model, this paper proposes a fault diagnosis method of rolling bearing based on multiscale convolutional neural network (MCNN) and

Purpose This study aims to investigate the influence of surface roughness and viscosity on micropitting and their influence sequence. Design/methodology/approach Specimens were made of carburized and quenched 18CrNiMo7-6, and different surface roughness was obtained by grinding and shot peening. Tests were carried out on a rolling-sliding tribometer, with different viscosity lubricants and a heavy

Purpose This paper aims to reveal the tribochemical reaction mechanism on the nano-cutting interface between HMX crystal and diamond tool. Design/methodology/approach Molecular dynamics simulation of HMX crystal nano-cutting by the reactive force field is carried out in this paper. The affinity of activated atoms and friction damage at the different interface have been well identified by comparing

Purpose The purpose of this paper is to improve lubrication and anti-corrosion properties of the water-in-oil (W/O) microemulsion for rolling of copper strip and sheet to replace the traditional rolling oil. Design/methodology/approach The W/O microemulsion is prepared by using hydrogenated base oil, a deionized aqueous solution of 0.03 mol/L of Na2SO4 and composite emulsifier such as Sp20, Tx-7 or

Purpose This paper aims to experimentally investigate the film-forming capability of base oils containing poly-methacrylate (PMA) and poly-isobutene (PIB), in a point contact under pure rolling. Design/methodology/approach By using the relative light intensity method, the film thickness is calculated from the interferometer images which are captured by multiple-contact optical elastohydrodynamic lubricated

Purpose The lubrication of the high-speed reducer of an electric vehicle is investigated. The specific contents include visualization of the flow field inside reducer, lubrication evaluation of bearings and efficiency experiment. Design/methodology/approach The flow field inside reducer at five working conditions: straight, uphill, downhill, left lean and right lean is simulated by smoothed particle

Purpose This study aims to investigate the effects of single dent on the film thickness and pressure in elastohydrodynamically lubricated (EHL) point contacts by numerical analysis. Design/methodology/approach The governing equations of single dent were established and then the variations of the film thickness and pressure induced by the applied load, the entrainment velocity and the ball radius were

Purpose The purpose of this paper is to prepare Ti(C,N) coatings on TA15 treated and not treated by shot peening using double glow plasma alloying technique. The effect of shot peening on the wear behavior of Ti(C,N) coatings is discussed. Design/methodology/approach The Ti(C,N) coatings were prepared by double glow plasma alloying technique on two different TA15 substrate; one is shot peened and the

Purpose This paper aims to study line-contact elastohydrodynamic grease lubrication properties of surface-textured rollers as well as the effect of different crown widths (dw) on oil film thickness under textured conditions. Design/methodology/approach The laser processing method was used to make the micro-texture on the surface of GCr15 steel rollers; lithium grease was used as the lubricant, and

Purpose This paper aims to propose a numerical method to calculate the convective heat transfer coefficient of spiral bevel gears under the condition of splash lubrication and to reveal the lubrication and temperature characteristics between the gears and the oil-air two-phase flow. Design/methodology/approach Based on computational fluid dynamics, the multiple reference frames (MRF) method was used