Creat membership Creat membership
Sign in

Forgot password?

  • Forgot password?
    Sign Up
  • Confirm
    Sign In
home > search

Now showing items 1 - 16 of 53

  • A Review on the Research Progress of Nano Organic Friction Materials

    Liu, Yang   Bao, Jiusheng   Hu, Dongyang   Ge, Shirong   Yin, Yan   Liu, Tonggang  

    Download Collect

    Disclosed is a coal mining machine attitude control method based on a coal seam geographic information system. The method comprises: establishing an association model between a cutter undercut adjustment amount of a lower drum (4) of a coal mining machine and a roll angle variation amount in attitude information of the coal mining machine (3); establishing a coal seam geographic information system for a working face to obtain a curve of a coal seam roof (1) and a curve of a coal seam floor (2) in an advancing direction of the coal mining machine; and locating slope-change points on the coal seam floor curve to achieve segmental linearization of the coal seam floor curve. By employing a coal mining machine positioning technique integrated with geological environment information to obtain real-time position and attitude information of a coal mining machine, and utilizing an association model between a cutter undercut adjustment amount of a lower drum of a coal mining machine and a roll angle variation amount in attitude information of the coal mining machine, the present invention obtains, by means of computation, an undercut adjustment amount of the lower drum of the coal mining machine to control the attitude of the coal mining machine. The method of the present invention effectively combines attitude control of a coal mining machine and dip angle identification of a coal seam, such that a roll angle of an attitude of the coal mining machine remains consistent with the dip angle of the coal seam.
    Download Collect
  • Friction and wear behavior of nitrogen ion implanted UHMWPE against ZrO2 ceramic

    Ge, Shirong   Wang, Qingliang   Zhang, Dekun   Zhu, Hua   Xiong, Dangsheng   Huang, Chuanhui   Huang, Xiaolong  

    As the osteolysis induced by polyethylene wear debris is the main cause of long-term failure of total joint replacements, increasing the wear resistance of ultrahigh molecular weight polyethylene (UHMWPE) will be very important to obtain high quality artificial joint. In this paper, we performed nitrogen ion implantation on UHMWPE with ion doses of 5–125×1014/cm2. The surface hardness and contact angle on implanted UHMWPE surface were measured. A ball-slid-on-disc tribometer was run, as a comparative test method, to observe the tribological behaviors of ion implanted UHMWPE against ZrO2 ceramic in dry friction and plasma lubrication. Meanwhile, the profiles of the worn groove on UHMWPE surface were scanned.
    Download Collect

    A bending fatigue damage monitoring system for a steel wire rope under the action of corrosion-alternating load coupling comprises a drive system, an alternating force loading system, a reversing control system, a surrounding angle adjustment system, a corrosive liquid adding system, a steel wire rope (15) and a steel wire rope state monitoring system. The monitoring system can carry out a bending fatigue test for the steel wire rope under the action of corrosion-alternating load coupling, and performs quantitative monitoring on internal damage of the steel wire rope and reveals a bending fatigue damage failure mechanism of the steel wire rope. The monitoring system can be used for exploring a dynamic contact between the steel wire rope and a friction liner of a friction wheel under a working condition of simulating mine hoisting, a local microslip amplitude and the dynamic tension evolution of the steel wire rope. This provides a piece of effective experimental equipment for the quantitative analysis of the bending fatigue failure characteristic of the steel wire rope under a complicated working condition; and the system is simple and convenient in operation, complete in functions and good in effect.
    Download Collect
  • Tribological behavior and mechanism of a magnetic conductive brake pair under action of alternating magnetic field

    Bao, Jiusheng   Huang, Shan   Liu, Yang   Ge, Shirong   Yin, Yan   Liu, Tonggang  

    Download Collect
  • The impact wear-resistance enhancement mechanism of medium manganese steel and its applications in mining machines

    Ge, Shirong   Wang, Qingliang   Wang, Junxiang  

    Download Collect
  • Biodegradation behavior and tribological properties of ultrahigh molecular weight polyethylene stabilized with α-tocopherol

    Kang, Xueqin   Yao, Chi   Ge, Shirong  

    Download Collect
  • Fretting wear behavior of nitrogen ion implanted titanium alloys in bovine serum lubrication

    Luo, Yong   Ge, Shirong  

    Nitrogen ion implantation was performed on biomedical titanium alloys by using of the PBII technology to improve the surface mechanical properties for the application of artificial joints. The titanium nitride phase was characterized with X-ray photoelectron spectroscopy (XPS). The nanohardness of the titanium alloys and implanted samples were measured by using of in-situ nano-mechanical testing system (Triboindenter). Then, the fretting wear of nitrogen ion implanted titanium alloys was done on the universal multifunctional tester (UMT) with ball-on-flat fretting style in bovine serum lubrication. The fretting wear mechanism was investigated with scanning electron microscopy (SEM) and 3D surface profiler. The XPS analysis results indicate that nitrogen diffuses into the titanium alloy and forms a hard TiN layer on the Ti6Al4V alloys. The nanohardness increases from 6.40 to 7.7 GPa at the normal load of 2 mN, which reveals that nitrogen ion implantation is an effective way to enhance the surface hardness of Ti6Al4V. The coefficients of friction for Ti6Al4V alloy in bovine serum are obviously lower than that in dry friction, but the coefficients of friction for nitrogen ion implanted Ti6Al4V alloy in bovine serum are higher than that in dry friction. Fatigue wear controls the fretting failure mechanism of nitrogen ion implanted Ti6Al4V alloy fretting in bovine serum. The testing results in this paper prove that nitrogen ion implantation can effectively increase the fretting wear resistance for Ti6Al4V alloy in dry friction, and has a considerable improvement for Ti6Al4V alloy in bovine serum lubrication. (C) 2009 Elsevier Ltd. All rights reserved.
    Download Collect
  • Design of a frictional-electromagnetic compound disk brake for automotives

    Huang, Shan   Bao, Jiusheng   Ge, Shirong   Yin, Yan   Liu, Tonggang  

    According to the disadvantages of serious wear and heat fade of friction pad in frequent and high speed braking of friction brakes, and the insufficient power of electromagnetic brakes in low speed braking, a novel frictional-electromagnetic compound disk brake which combines both of these two brake principles is proposed for automotives in this paper. The excitation coils are designed based on the Zhang Yicheng theory model, and the compound brake prototype is manufactured based on the self-made magnetic brake pads and existing automotive brakes. The magnetic field and dynamic of the brake are simulated by using COMSOL Multiphysics software. The frictional-electromagnetic compound brake tests are implemented on the reconstructive disk brake simulation test bench. The experimental results show that the friction braking torque accounts for more than 90% of the compound braking torque in the process of compound braking, and the trend of the change is the same as that of the compound braking torque. When the initial braking speed exceeds 75 km/h, the electromagnetic braking torque does not increase with the increase in speed, instead, it decreases slightly because of demagnetization. The designed frictional-electromagnetic compound disk brake has good braking performance.
    Download Collect
  • The mechanical property and tribological behavior of UHMWPE: Effect of molding pressure

    Wang, Shibo   Ge, Shirong  

    The ultra-high molecular weight polyethylene (UHMWPE) samples were prepared with three pressure of 10 MPa, 15 MPa and 20 MPa in this paper. Then these samples were applied to do bulk hardness measurement, scratch testing and punch testing. Meanwhile, the friction and wear behavior of IJHMWPE samples were studied by using Of Si3N4 ball sliding on UHMWPE disc under plasma lubrication. The eight-figure sliding track was generated on the UNIT tribotester. The experiment results indicate that the molding pressure has significantly influence on the mechanical property and tribological behavior of UHMWPE samples. Among three UHMWPE samples prepared with pressure of 10 MPa, 15 MPa and 20 MPa, the UHM)VPE sample molded in pressure of 15 MPa obtains the highest values of bulk hardness up to 28.5 MPa, the scratch coefficients up to 3.41 and the punch breaking loads up to 201.6 N. The coefficients of friction of this UHMWPE sample result in the lowest value around 0.025, the lowest wear mass loss of 0.93 mg is obtained for 10,000 cycles testing. There is no apparent difference in the frequency distribution of worn particles with respect to particle size for the UHMWPE samples from three levels of molding pressure. The wear particle size concentrates at about 8 mu m. The microstructures of UHMWPE are influenced by compression pressure. Low compression pressure of 10 MPa results in grain defects to reduce the bonding strength between grain boundaries. The compression pressure of 20MPa results in stress-induced orientation microstructure in UHMWPE. (C) 2007 Published by Elsevier B.V.
    Download Collect
  • The changes of fractal dimensions of frictional signals in the running-in wear process

    Zhu, Hua   Ge, Shirong   Cao, Xichuan   Tang, Wei  

    The running-in wear experiments were preformed on the pin-on-disc tester. Time series signals of both frictional force and vibration were distilled by the computer data-collecting system, at the same time the fractal dimensions of the signals were obtained by the correlation-dimension method. It was found that the signals had an apparent fractal nature. Their fractal dimensions altered with the change of friction time, that is, increased gradually with the running-in procedure going on to reach its maximum ultimately. This indicated that the running-in process was ended from the initial friction of two surfaces to their fitted state (i.e. running-in state). In addition, the fractal dimension of friction signals was consistent with the fractal dimension of worn surfaces in the running-in process. So we can predict the progress of running-in wear process and identify the running-in state of a friction pair by the change of fractal dimension of frictional signals. (c) 2007 Published by Elsevier B.V.
    Download Collect
  • Dry sliding friction and wear properties of B4C particulate-reinforced Al-5083 matrix composites

    Tang, Feng   Wu, Xiaoling   Ge, Shirong   Ye, Jichun   Zhu, Hua   Hagiwara, Masuo   Schoenung, Julie M.  

    Pin-on-disk dry sliding wear tests a, sliding speeds ranging from 0,6 to 1,25 m/s and under loads ranging from 3.98 to 6.37 MPa (50-80 N) were conducted for pin specimens of composites with Al-5083 matrices reinforced with 5 and 10 wt.% B4C particles. The wear rate of the composite with 10 wt.% B4C was approximately 40% lower than that of the composite with 5 wt.% B4C under the same test condition. Two stages were observed in the reduction of pin length/sliding distance curves in several specimens, with the length reduction rate in the first stage being one to two orders of magnitude lower than that in the second stage. The low length reduction rate in the first stage corresponded with a flat stage with a low coefficient of friction (COF) in the COF/sliding distance curve. (c) 2007 Elsevier B.V. All rights reserved.
    Download Collect
  • Characterization and Identification of Coal and Carbonaceous Shale Using Visible and Near-Infrared Reflectance Spectroscopy

    Yang, En   Ge, Shirong   Wang, Shibo  

    Because of the high organic carbon concentration in carbonaceous shale, a large proportion of carbonaceous shales are often misclassified into coals using visible and near-infrared (VIS-NIR) reflectance spectroscopy in the field of coal-gangue identification of hyperspectral remote sensing of coal mine. In order to study spectral characterization of coal and carbonaceous shale, three bituminite samples and three carbonaceous shales were collected from a coal mine of China, and their spectral reflectance curves were obtained by a field spectrometer in the wavelength range of 350-2500 nm. Only one carbonaceous shale could be easily identified from the three bituminite samples according to obvious absorption valleys near 1400 nm, 1900 nm, and 2200 nm of its reflectance curve while the other two carbonaceous shales have similar reflectance curves to the three bituminite samples. The effect of carbon concentration on reflectance curve was simulated by the mixed powder of ultralow ash bituminite and clay in 0.5 mm grain size under various mixing ratios. It was found that absorption valleys near 1400 nm, 1900 nm, and 2200 nm of the mixed powder become not obvious when the bituminite content is more than 30%. In order to establish an effective identification method of coal and carbonaceous shale, 250 other samples collected from the same coal mine were divided into 150 training samples and 100 prediction samples. Principal component analysis (PCA) and Gauss radial basis kernel principal component analysis (GRB-KPCA) were employed to extract principal components (PCs) of continuum removed (CR) spectra of the training samples in eight selected wavelength regions which are related to the main mineral and organic compositions. Two support vector machine-(SVM-) based models PCA-SVM and GRB-KPCA-SVM were established. The results showed that the GRB-KPCA-SVM model had better identification accuracies of 94% and 92% for powder and nature block prediction samples, respectively.
    Download Collect
  • Triboelectrification studies of skin and skin cream using Kelvin probe microscopy

    Tang, Wei   Bhushan, Bharat   Ge, Shirong  

    Static charge of skin surface has a significant effect on skin feel, look, and health. For this reason, controlling the charge buildup is an important issue in the commercial skin care industry. In this study, a systematic triboelectrification study of skin and skin cream was carried out. The surface potential of virgin skin and cream treated skin was measured using the Kelvin probe microscopy with an atomic force microscope. Since skin surface is not microscopically smooth, many interactions take place at microasperities, and there are also many microspherical particles in the environment interacting with skin surface. Triboelectrification of skin was studied by charging skin surface using a polystyrene plate on the macroscale and a polystyrene microsphere on the microscale. Since triboelectric charge is expected to be a function of normal load, velocity, and rubbing time, the influence of velocity, normal load, and rubbing time on the surface potential of virgin skin and cream treated skin were studied. Finally, charging mechanisms are discussed. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3374341]
    Download Collect
  • Experimental research on the tactile perception from fingertip skin friction

    Chen, Si   Ge, Shirong  

    Skin friction is a main perception channel for humankind to recognize object surface properties. However, the relationship between tactile perception and skin friction is a typical bio-tribology interdisciplinary problem, which is rarely studied both in biology and tribology fields. In order to study the brain stimulation response to the fingertips sliding friction, cognitive related fingertip friction testing was carried out, and the tactile perception evoked by the friction and vibration of various surface textures was investigated in this paper, human subjective tactile experiments was carried out through twenty volunteers testing for the tactile perception of surface properties, focused on three fabric samples (cotton, linen and silk) and three paper samples (photo paper, (craft paper and normal paper). The friction coefficient and frictional vibration signals were measured, and the brain response signals stimulated by the fingertip friction were simultaneously recorded and analyzed. The research works in this paper are beneficial for the deep understanding of tactile perception mechanism by fingertips, and building up a biomimetic model for smart robotic fingers. The research results indicate that the cerebral cortex responds sensitively to the variations in fingertips frictional force and vibration amplitudes. The human tactile perception is very sensitive to the fabric texture properties, which are described by the dimensions such as rough-smooth, coarse-fine and complex-uniform. The higher values of the fabric texture dimensions, the lower values in friction coefficient, and the more sensitive of tactile perception for the surface textures. Furthermore, it is noticed that the amplitude and distribution of brain signals response, i.e. ERPs (event related potentials) evoked by fingertip friction, is affected by the surface texture or friction coefficient. It is found that the response sensibility shown on the beginning peaks of ERP waveform has strong relation to the frictional stimulus on fingertip friction. The parameter of P3 latency (i.e. the third positive peak of ERP) is the distinct identifying information for the tactile perception of surface textures. (C) 2016 Elsevier B.V. All rights reserved.
    Download Collect
  • Experiment Investigation on Fretting Wear and Wear Debris Performance for the Stem-Cement Interface

    Zhang, Lanfeng   Ge, Shirong   Liu, Hongtao  

    After the interface debonding, the body protein fluid is subsequently pumped into stem-cement fretting wear interface, serving as the lubricant. On the stem surface, whether there is the influence of protein absorption on fretting wear or not is considered in this study. The biotribological properties at the stem-cement interface were investigated by SEM. The result of hysteresis loops shows that elasticity and plasticity performance of the frictional interface materials can be damaged by fretting fatigue and material energy dissipation will increase periodically. The wear quantity of cement is mainly influenced by load and displacement. The maximum wear loss of bone cement could reach 1.997 mg. Bone cement and titanium alloy wear debris, whose size distributions are widely spread from 1 to 110 mu m and 5 to 150 mu m, respectively, are shaped like tuber, tear, sheet, strip, and sphere, which will induce the osteocyte damage.
    Download Collect
1 2 3 4


If you have any feedback, Please follow the official account to submit feedback.

Turn on your phone and scan

Submit Feedback