Hui Zhang

Xi'an Jiaotong University | XJTU · School of Mechanical Engineering

A surface with asymmetric microstructures for self-driven directional spreading of liquid has attracted keen interest from researchers in recent years for its great application prospects. Inspired by the jaws of tiny insects, such as ants, a surface textured with novel jaw-like microstructures as micro one-way valves is reported. These microstructu...

The synergistic effect of surface texturing and lubricants with various viscosity and polarity properties is an attractive and unexplored topic. In this study, surface texturing characterized by circular dimples has been manufactured on steel surfaces in advance, which can improve the lubrication of frictional units compared with the bare disc unde...

Recently, bioinspired mushroom or reentrant mushroom microstructures have attracted intersts of researchers for their amazing water superrepellence property. However, basic principles of exquisite microstructures design for improving water repellence are still lacking. This paper reports a novel 3D-printed biomimetic superhydrophobic surface with p...

Scale/scaly structures are commonly seen in living nature, such as loach and pangolin, and they generally play an important role in reducing friction between biosurfaces and their contacted solid/water. Hence, inspired by scale structures in biology, we propose a design of surface texturing with 3D delicate scaly structures to improve the tribologi...

This study aims at optimizing the boundary slip region on bearing sliders for improving tribological performance. Surface of the bearing slider are divided into a rectangular mesh, in which each rectangular grid is assumed to be local slip region or no-slip region, labeled as 1 or 0. Then, the Genetic Algorithm is performed to optimize the shape an...

This paper presents the effort to reduce friction and wear of gear washers under low-speed and heavy-load conditions by designing the arrangement of surface textures. The influence of distributional parameters of textures on load-bearing capacity and friction coefficient of gear washers are studied numerically to obtain a preferable surface texturi...

Injectable hydrogel provides a new advance on lubrication of artificial joints due to its in situ forming property and long-term release effect. The adaptability improvement of the injectable hydrogel is crucial for its successful application in joint prostheses without weakening its injectable performance. In this paper, we reported a thermosensit...

This paper reports a novel pocket-textured surface for improving the tribological properties of point contact under starved lubrication by possibly storing and releasing oil, and homogenizing the surface contact pressure. The ball-on-disk experimental results confirmed the coefficient of friction (COF) and wear reduction effect of such pocket-textu...

This paper aims to improve wear resistance of bare Babbitt modified by CuLa and evaluates the effect of different sliding modes on tribological properties of bare Babbitt, Babbitt modified by 0.5 wt% CuLa (marked by mbabbitt-1) and Babbitt modified by 1 wt% CuLa (marked by mbabbitt-2). First, bare Babbitt was modified with different content of CuLa...

Rapid and controllable sliding of droplets on anisotropic superhydrophobic surface has significant meaning in advanced science and technologies, thus being widely studied in recent years. Herewith, we reported a fabrication of micro- and nano- fractal superhydrophobic surface patterned with micro hydrophilic channels using laser direct writing meth...

A grooved texture surface was fabricated to enhance the wear resistance of the guide rail surface of molding machine. The effects of sand concentration in the oil and the groove width on the tribological properties were studied using a pin-on-disk tribometer. Surfaces with groove widths of 1000 μm (S1) and 1500 μm (S2) had lower friction coefficien...

The study proposes an effective oil layer method for improving the processing quality and the tribological behavior of laser textured surface. Experimental results suggest the oil layer method has the reduction effect on the coverage area of metallic oxide and the height of rim ridges/burrs of textures. Possible mechanisms are mainly attributed as:...

A simple and novel approach is proposed to control location, shape, contact angle, and sliding of droplet on superhydrophobic aluminum alloy surfaces scanned by laser. By firstly etched suitably, followed by coating with stearic acid, aluminum alloy surface is possible to exhibit the property of superhydrophobic behavior. Irradiating such surface w...

In this study, the distribution of circular concave textures on sectorial thrust bearing pads is optimized for improving load bearing capacity and reducing friction coefficient. Textures in a sector-shaped array are supposed to be existed or empty, labeled as 1 or 0. Then, the texture distribution is optimized according to a Genetic Algorithm. A di...

This paper aims to improve the tribological performance of journal bearings by optimizing the coverage area of circular microtextures in divergent region of the sleeve. A numerical model is proposed to calculate the friction coefficient and bearing load of textured journal bearings. The surface of the sleeve is divided into rectangular squares. Tex...

In this paper, three kinds of polymer, of epoxy resin (EP), phenolic resin (PF), and unsaturated polyester (UP), were used as fillers to prepare the laminated composite surface, and the tribological properties of a composite surface were studied under dry sliding condition. The results showed that: (i) the composites surface without MoS₂ exhibited...

Purpose The main purpose of this paper is to present the effort on developing a mixed elastohydrodynamic lubrication (EHL) model to study the tribological effect of asperities on rough surface. Design/methodology/approach In the model, with the use of the average flow Reynolds equation and the K-E elasto-plastic contact model, it allows predicti...

To improve the high-temperature tribological performance of the polymer composite, an oil-containing laminated composite was prepared bionically by adding the poly-α-olefin (PAO) oil into the polymer, and the oil-containing polymer was filled into the laminated grooved surface. The tribological performance of the composite was investigated on a pin...

A numerical approach was proposed for the optimization of shape contour of recessed surface texture under unidirectional sliding. The approach was developed based on a Genetic Algorithm to improve the tribological performance. Results indicated either bullet or fish shape to be the preferable texture shape contours. Analyses on the hydrodynamic pre...

An analytical numerical model to optimize the shape of concave surface texture for the achievement of low friction in reciprocating sliding motion has been developed. The model uses: (i) average Reynolds equation to evaluate friction coefficient and (ii) genetic algorithm (GA) to optimize and obtain several preferable texture shapes. Analysis of di...

Purpose – The main purpose of this paper is to understand and model the hydrodynamic influence of surface textures on journal bearings. Design/methodology/approach – In the model, a rectangular array of circle dimples is used to modify the film thickness expression. In full film and cavitation regions, classical Reynolds equation and Reynolds boun...

An analytical numerical model is specifically developed to understand the tribological behavior of textured surface in mixed lubrication regime. The model employs the average flow Reynolds equation and an elasto-plastic contact model, established on the basis of finite element analysis, to calculate (i) the hydrodynamic pressure in full film region...

This paper presents the development of a numerical model for high speed and water lubricated journal bearings with different boundary slip arrangements. The effect of boundary slip and its possible mechanism are analyzed and discussed. The results suggest that a suitable combination of slip/no-slip surfaces on the sleeve of a journal bearing enable...

Aiming at improving the tribological performances of sliding bearings in mixed or starved lubrication regime, textures in square and linear radiating arrays are ablated on the surface of Babbitt alloy disks by laser radiation. Series of pin-on-disk wear tests and computational fluid dynamics (CFD) analysis are conducted to investigate the influence...

This paper, based on the two-component slip model, numerically analyzes the tribology performances of journal bearings with boundary slip/no-slip regions on the condition of high speed water lubrication. It is demonstrated that journal bearings with a whole slip sleeve reduce the friction drag and the load carrying capacity. Bearings with a slip/no...

Circular spot was irradiated by a Nd:YAG laser under a particular operational setup producing crater-like (or doughnut-like) feature, which was anticipated to generate favorable hydrodynamic effects in wet lubrication condition. It was used to ablate the pattern in either an in-line (IN) or staggered (ST) arrangement on DF2 tool steel plates. The i...