Tribological characteristics of micro-ball bearing with V-shaped grooves coated with ultra-thin protective layers

Oh, Dae San; Kang, Kyoung‐Tak; Kim, Hyun Joon; Kim, Jae Kang; Won, Moon Sub; Kim, Dae Eun

doi:10.1016/j.triboint.2017.11.014

Cited by 15 publications

(18 citation statements)

References 39 publications

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“…Owing to scientific developments and discoveries of new materials, the significance of films has shifted from art to technology. In present times, most of engineering disciplines incorporate the use of thin films in various applications including thin film photovoltaics for efficient solar power conversion [2][3][4][5][6][7], thin film lithium batteries for consumer portable electronics [8,9], semiconductor thin films for micro-and nano-electronics [10], thin film optical coatings [11], thin films for high resolution displays [12] and thin films for tribological and protective coatings applications [13], to name a few.…”

Section: Introductionmentioning

confidence: 99%

Evidence of substrate roughness surface induced magnetic anisotropy in Ni80Fe20 flexible thin films

Belusky

Lepadatu

Naylor

et al. 2019

Journal of Magnetism and Magnetic Materials

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Experimental and computational evidence of a surface roughness induced magnetic anisotropy in NiFe thin films coated onto substrates of various surface roughnesses is reported. Magnetic coercive fields of 15 nm NiFe thin films coated on substrates with approximately 7 nm average roughness were remarkably 233% larger than identical thin films coated onto smooth substrates with < 1 nm average roughness. The NiFe films coated onto rough substrates developed hard and easy axes, normally non-existent in NiFe Permalloy. A linear correlation of the incline angles of the hard axis hysteresis loops to the average roughness values of the individual substrates was observed, with 99% correlation level. Using a modified micromagnetics theory that incorporates the effects of surface roughness, it is shown the observed magnetic anisotropy arises due to the spatial anisotropy of the surface roughness, resulting in an effective in-plane uniaxial magnetic anisotropy with energy density up to 15 kJ/m 3 .

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Section: Introductionmentioning

confidence: 99%

Evidence of substrate roughness surface induced magnetic anisotropy in Ni80Fe20 flexible thin films

Belusky

Lepadatu

Naylor

et al. 2019

Journal of Magnetism and Magnetic Materials

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“…Attempts have been made by the researchers for achieving the effective lubrication by employing surface textures/micro-grooves on the bearing races, [4][5][6][7][8][12][13][14][15] holes and circumferentially micro-grooves on balls 16 and adding certain nano/micro particles in the lubricants. [17][18][19][20][21][22] Significant reductions in frictional torque, rise in temperature and vibration level are found with textured races of ball bearings.…”

Section: Introductionmentioning

confidence: 99%

Performance improvement of a radial ball bearing using a micro-groove on stationary outer race

Gouda

Tandon

Pandey

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part C:

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For achieving improved lubrication in a radial ball bearing (BB1B 420206), a circumferential micro-groove inside the stationary outer race has been conceived based on finite element analysis to facilitate the availability of grease and to reduce the stresses at the contacts and it has been fabricated to conduct the experiments. To understand the effect of this micro-groove filled with grease on the film formation, frictional torque, and bearing dynamics, experiments were performed for measuring these variables at different operating parameters ( pH = 0.35–1.2 GPa; speed = 1.4–4.2 m/s). Capacitance based approach, load cell, and miniature accelerometer have been employed to measure the film thickness, frictional load and vibrations, respectively. The results achieved with bearings with micro-groove on outer races have been compared with bearings having the conventional races at the identical operating parameters. Reductions of 14%–41% in vibrations, up to 11.2% increase in film thickness (i.e. 11% reduction in the capacitance), and in the range of 15%–30% reduction in the frictional torque have been obtained as compared to conventional bearing cases.

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“…Besides the surface defects, the normal and shear stresses present on the abrasive plate could cause the propagation of inner cracks during the finishing process of spherical parts made of ceramic materials [6]. Moreover, adhesion of the debris and chemical diffusion between the workpiece and abrasive plates were observed, which could also cause deterioration of geometric precision and mechanical properties of machined surfaces [7].…”

Section: Introductionmentioning

confidence: 99%

Polishing of Silicon Nitride Ceramic Balls by Clustered Magnetorheological Finish

Xiao

Mei

et al. 2020

Micromachines

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In this study, a novel finishing method, entitled clustered magnetorheological finish (CMRF), was proposed to improve surface finish of the silicon nitride ( Si 3 N 4 ) balls with ultra fine precision. The effects of different polishing parameters including rotation speeds, eccentricities and the machining gaps on surface finish of Si 3 N 4 balls were investigated by analyzing the roughness, sphericity and the micro morphology of the machined surface. The experimental results showed that the polishing parameters significantly influenced the surface finish. The best surface finish was obtained by using the polishing parameters: the machining gap of 0.8 mm, the eccentricity of 10 mm and the rotation ratio of 3/4. To further investigate the influence of the polishing parameters on the surface finish, an analytical model was also developed to analyze the kinematics of the ceramic ball during CMRF process. The resulting surface finish, as a function of different polishing parameters employed, was evaluated by analyzing the visualized finishing trace and the distribution of the contact points. The simulative results showed that the distribution and trace of the contact points changed with different polishing parameters, which was in accordance with the results of experiments.

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Tribological characteristics of micro-ball bearing with V-shaped grooves coated with ultra-thin protective layers

Cited by 15 publications

References 39 publications

Evidence of substrate roughness surface induced magnetic anisotropy in Ni80Fe20 flexible thin films

Evidence of substrate roughness surface induced magnetic anisotropy in Ni80Fe20 flexible thin films

Performance improvement of a radial ball bearing using a micro-groove on stationary outer race

Polishing of Silicon Nitride Ceramic Balls by Clustered Magnetorheological Finish

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