Investigation on surface morphology and tribological property generated by vibration assisted strengthening on aviation spherical plain bearings

Author(s):  
Zewei Yuan ◽  
Yue Qin ◽  
Kai Cheng ◽  
Wenzhen Zhao ◽  
Peng Zheng

The extreme and complex working conditions require aviation spherical plain bearings not only to have high machining accuracy and low surface roughness, but also to possess high surface microhardness and lubricant retaining capability. This paper presents a vibration assisted strengthening approach to achieving the synergistic effects of the surface property-improving and appearance-improving. The research attempts to answer how vibration assisted strengthening technique can improve the surface tribological properties of aviation spherical plain bearing components particularly in light of proposing the flat-headed asperity distribution model and the corresponding elastic–plastic contact modelling for the special processed surface morphology. Subsequently, the models are corroborated by the experimental results of characterizing the surface morphology produced by vibration assisted strengthening with different parameters such as rolling times and rolling static force. The surface tribological properties of spherical plain bearing specimens were studied by employing the UMT-TriboLab platform. The theoretical analysis and experimental results indicate that the surface asperities of spherical plain bearing components processed with repeated high frequency strikes present a flat-headed distribution but not Gauss distribution. It characterizes with a marked majority of produced small asperities with similar height, which is beneficial to frictional couple contacts and a lot of original valleys retaining lubricants. The processing technique contributes to increasing the surface microhardness by 20% and decreasing the surface roughness from about Ra 0.4 µm to below Ra 0.1 µm. The ball-on-flat friction tests demonstrate that both the special flat-headed surface structure and the elevated microhardness can attribute the improvement of tribological properties and wear resistance performance of spherical plain bearings.

2014 ◽  
Vol 556-562 ◽  
pp. 733-737
Author(s):  
Yan Jun Li ◽  
Bao Fu Li

Against the problem of large machining error and low productivity of aluminum alloy spherical plain bearing, the paper is concentrated on building finite element model in MATLAB to research the radial and axial deformation law under various cutting conditions with theories of heat transfer, isoparametric element and functional variational method, providing theoretical and data support to enhance machining accuracy of spherical plain bearing outer ring.


2021 ◽  
Vol 2137 (1) ◽  
pp. 012033
Author(s):  
Guang Li ◽  
Zhipeng Wei ◽  
Junlong Wang ◽  
Yangyang Zhang ◽  
Chen Wang ◽  
...  

Abstract In this paper, a nanosecond fiber pulse laser is used to carry out the experimental study on laser weight removal of ZL205A aluminum alloy gyro rotor. By optimizing the process parameters of laser weight removal, better surface morphology was obtained. The effects of surface roughness, metallographic structure and hardness of samples before and after laser deweighting were analyzed. The experimental results show that the laser weight removal does not affect the matrix properties of ZL205A aluminum alloy. The laser de-weight technology is suitable for the balance of ZL205A aluminum alloy gyro rotor.


2014 ◽  
Vol 543-547 ◽  
pp. 3904-3909
Author(s):  
Yan Jun Li ◽  
Bao Fu Li

Against the problem of large machining error and low productivity of aluminum alloy spherical plain bearing, the paper is concentrated on building finite element model in MATLAB to research the radial and axial deformation law under various cutting conditions with theories of heat transfer, isoparametric element and functional variational method, providing theoretical and data support to enhance machining accuracy of spherical plain bearing outer ring.


2020 ◽  
Vol 50 (6) ◽  
pp. 775-785
Author(s):  
TingMei WANG ◽  
Bo LIANG ◽  
WeiHua ZHAO ◽  
LiMing TAO ◽  
WanHua CHEN ◽  
...  

2008 ◽  
Vol 389-390 ◽  
pp. 338-343 ◽  
Author(s):  
Y. Gao ◽  
J. Xin ◽  
H. Lai

An actively cooled and activated cooling approach is proposed and examined in this project in order to deal with the problems associated with methods such as the cryogenic cooling method. It is also aimed to further improve the surface quality of the workpiece after grinding by combining the advantages of the existing cooling methods. Both computational and experimental studies were conducted for grinding the brittle materials with the proposed approach. Optical examinations were used to study the surface morphology. The experimental results show that the surface quality can be improved by up to 23.75% on average in terms of surface roughness Ra. The computational test reveals that the heat can be taken away more effectively by the proposed approach.


2012 ◽  
Vol 565 ◽  
pp. 615-620
Author(s):  
Bin Shen ◽  
Liang Wang ◽  
Su Lin Chen ◽  
Fang Hong Sun

The CVD diamond/diamond-like carbon composite film is fabricated on the WC-Co substrate by depositing a layer of Diamond-like Carbon film on the surface of conventional Micro- or Nano-crystalline diamond film. The hot filament chemical vapor deposition (HFCVD) method and vacuum arc discharge with a graphite cathode are adopted respectively to deposit the MCD/NCD and DLC films. A variety of characterization techniques, including filed emission scanning electron microscope (FE-SEM) and Raman spectroscopy are employed to investigate the surface morphology and atomic bonding state of as-deposited MCD/DLC and NCD/DLC composite film. The results show that both MCD/DLC and NCD/DLC composite films present similar surface morphology with the MCD and NCD films, except for scattering a considerable amount of small-sized diamond crystallites among the grain boundary area. The atomic-bonding state of as-deposited MCD/DLC and NCD/DLC composite films is determined by the top-layered DLC film, which is mainly consisted of amorphous carbon phase and no discernible sp3 characteristic peak can be observed from their Raman spectrum. Furthermore, the tribological properties of as-deposited MCD/DLC and NCD/DLC composite films is examined using a ball-on-plate reciprocating friction tester under both dry sliding and water-lubricating conditions, comparing with conventional DLC, MCD and NCD films. Silicon nitride balls are used as counterpart materials. For the CVD diamond/DLC composite films, the self-lubricating effect of top-layered DLC film is beneficial for suppressing the initial friction peak, as well as shortening the run-in period. The average friction coefficients of MCD/DLC and NCD/DLC composite films during stable sliding period are 0.07 and 0.10 respectively in dry sliding; while under water-lubricating condition, they further decreases to 0.03 and 0.07.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110118
Author(s):  
Zenan Chu ◽  
Tao Wang ◽  
Qiang He ◽  
Kai Zhao

To solve the problems of low processing efficiency and poor glass surface quality when using rare earth polishing powder to grind super-hard K9 glass. The potential, phase structure, surface morphology, and particle size distribution of the nano-rare earth polishing powder were characterized. Compare the evaluation indexes such as polishing efficiency, surface morphology, and contact angle after the polishing process is changed. The results of the comparative study show that the average surface roughness of the glass after heating ultrasonic polishing process is 0.9064 nm, the polishing rate reaches 0.748 μm/min, the average surface roughness of the glass without heating ultrasonic polishing process is 1.3175 nm, and the polishing rate reaches 0.586 μm/min, the ultrasonic assisted polishing process is superior to the conventional polishing process. The heating ultrasonic method provides experimental basis for precise and rapid processing.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Jinlong Jiang ◽  
Qiong Wang ◽  
Yubao Wang ◽  
Zhang Xia ◽  
Hua Yang ◽  
...  

The titanium- and silicon-codoped a-C:H films were prepared at different applied bias voltage by magnetron sputtering TiSi target in argon and methane mixture atmosphere. The influence of the applied bias voltage on the composition, surface morphology, structure, and mechanical properties of the films was investigated by XPS, AFM, Raman, FTIR spectroscopy, and nanoindenter. The tribological properties of the films were characterized on an UMT-2MT tribometer. The results demonstrated that the film became smoother and denser with increasing the applied bias voltage up to −200 V, whereas surface roughness increased due to the enhancement of ion bombardment as the applied bias voltage further increased. The sp3carbon fraction in the films monotonously decreased with increasing the applied bias voltage. The film exhibited moderate hardness and the superior tribological properties at the applied bias voltage of −100 V. The tribological behaviors are correlated to the H/E or H3/E2ratio of the films.


2017 ◽  
Vol 8 (2) ◽  
pp. 179-187 ◽  
Author(s):  
Kankan Ji ◽  
Xingquan Zhang ◽  
Shubao Yang ◽  
Liping Shi ◽  
Shiyi Wang ◽  
...  

Purpose The purpose of this paper is to evaluate surface integrity of quenched steel 1045 ground drily by the brazed cubic boron nitride (CBN) grinding wheel and the black SiC wheel, respectively. Surface integrity, including surface roughness, sub-surface hardness, residual stresses and surface morphology, was investigated in detail, and the surface quality of samples ground by two grinding wheels was compared. Design/methodology/approach In the present work, surface integrity of quenched steel 1045 machined by the CBN grinding wheel and the SiC wheel was investigated systematically. All the specimens were machined with a single pass in the down-cutting mode of dry condition. Surface morphology of the ground specimen was observed by using OLYMPUS BX51M optical microscopy. Surface roughness of seven points was measured by using a surface roughness tester at a cut-off length of 1.8 mm and the measurement traces were perpendicular to the grinding direction. Sub-surface micro-hardness was measured by using HVS-1000 digital micro-hardness tester after the cross-section surface was polished. The residual stress was tested by using X-350A X-ray stress analyzer. Findings When the cut depth is increased from 0.01 to 0.07 mm, the steel surface machined by the CBN wheel remains clear grinding mark, lower roughness, higher micro-hardness and higher magnitude of compressive stress and fine microstructure, while the surface machined by the SiC grinding wheel becomes worse with increasing of cut depth. The value of micro-hardness decreases, and the surface roughness increases, and the surface compressive stress turns into tensile stress. Some micro-cracks and voids occur when the sample is processed by the SiC grinding wheel with cut depth 0.07 mm. Originality/value In this paper, the specimens of quenched steel 1045 were machined by the CBN grinding wheel and the SiC wheel with various cutting depths. The processing quality resulted from the CBN grinding wheel is better than that resulted from the SiC grinding wheel.


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