Starved lubrication of isoviscous rigid elliptical contacts

In this study, atmospheric plasma spray was employed to deposit TiO2–SiAlON ceramic coating on 316 stainless steel. The phases and microstructure of the ceramic coating were investigated. Additionally, comparative studies on the tribological performances of the substrate and the ceramic coating, under both dry and starved lubrication conditions, were carried out. The SiAlON phase was preserved, while partial TiO2 anatase was transformed to rutile phase. The wear rate of the coating was roughly 1/3 of that of the substrate under both conditions. The wear mechanisms of the ceramic coating were surface fracture and abrasive wear in both cases, and the coating under starved lubrication underwent less abrasion. The pores in the coating served as micro-reservoirs, forming an oil layer on the mating surface, and improving tribological properties during sliding.

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Effects of Micro Dimple’s Topography Parameters on Wear Resistance of Laser Textured AlCrN Coating Under Starved Lubrication Condition

Surface Topography Metrology and Properties ◽

10.1088/2051-672x/ac0ba0 ◽

2021 ◽

Author(s):

Jie Yang ◽

Hao Fu ◽

Yonghong Fu ◽

Jiaxing Jiang ◽

Yuyang He ◽

...

Keyword(s):

Wear Resistance ◽

Lubrication Condition ◽

Starved Lubrication

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A Starved Mixed Elastohydrodynamic Lubrication Model for the Prediction of Lubrication Performance, Friction and Flash Temperature With Arbitrary Entrainment Angle

Journal of Tribology ◽

10.1115/1.4037844 ◽

2017 ◽

Vol 140 (3) ◽

Cited By ~ 10

Author(s):

Wei Pu ◽

Dong Zhu ◽

Jiaxu Wang

Keyword(s):

Surface Roughness ◽

Film Thickness ◽

Elastohydrodynamic Lubrication ◽

Industrial Applications ◽

Operating Conditions ◽

Flash Temperature ◽

Machined Surface ◽

Lubrication Performance ◽

Wide Range ◽

Starved Lubrication

In this study, a modified mixed lubrication model is developed with consideration of machined surface roughness, arbitrary entraining velocity angle, starvation, and cavitation. Model validation is executed by means of comparison between the obtained numerical results and the available starved elastohydrodynamic lubrication (EHL) data found from some previous studies. A comprehensive analysis for the effect of inlet oil supply condition on starvation and cavitation, mixed EHL characteristics, friction and flash temperature in elliptical contacts is conducted in a wide range of operating conditions. In addition, the influence of roughness orientation on film thickness and friction is discussed under different starved lubrication conditions. Obtained results reveal that inlet starvation leads to an obvious reduction of average film thickness and an increase in interasperity cavitation area due to surface roughness, which results in significant increment of asperity contacts, friction, and flash temperature. Besides, the effect of entrainment angle on film thickness will be weakened if the two surfaces operate under starved lubrication condition. Furthermore, the results show that the transverse roughness may yield thicker EHL films and lower friction than the isotropic and longitudinal if starvation is taken into account. Therefore, the starved mixed EHL model can be considered as a useful engineering tool for industrial applications.

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Analysis of Tribological Performance of Piston Ring Lubrication

ASME 2011 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2011-60036 ◽

2011 ◽

Author(s):

Yibin Guo ◽

Wanyou Li ◽

Dequan Zou ◽

Xiqun Lu ◽

Tao He

Keyword(s):

Film Thickness ◽

Friction Force ◽

Power Loss ◽

Piston Ring ◽

Design Parameters ◽

Oil Film ◽

Starved Lubrication ◽

Piston Ring Lubrication ◽

Cylinder Bore ◽

Lubrication Conditions

In this paper a mixed lubrication model considering lubricant supply conditions on cylinder bore has been developed for the piston ring lubrication. The numerical procedures of both fully flooded and starved lubrication were included in the model. The lubrication equations and boundary conditions at the end of strokes were discussed in detail. The effects of piston ring design parameters, such as ring face profile and ring tension, on oil film thickness, friction force and power loss under fully flooded and starved lubrication conditions due to available lubricant supply on cylinder bore were studied. The simulation results show that the oil available in the inlet region of the oil film is important to the piston ring friction power loss. With different ring face crown heights and tensions, the changes of oil film thickness and friction force were apparent under fully flooded lubrication, but almost no changes were found under starved lubrication except at the end of a stroke. In addition, the oil film thickness and friction force were affected evidently by the ring face profile offsets under both fully flooded and starved lubrication conditions, and the offset towards the combustion chamber made a large contribution to forming thicker oil film during the expansion stroke. So under different lubricant supply conditions on the cylinder bore, the ring profile and tension need to be adjusted to reduce the friction and power loss. Moreover, the effects of lubricant viscosity, surface composite roughness, and engine operating speed on friction force and power loss were also discussed.

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Wear Behavior of Medium-Carbon Steel with Different Laser-Textured Densities under Starved Lubrication

Coatings ◽

10.3390/coatings10121225 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1225

Author(s):

Fanming Zeng ◽

Yuting Liu ◽

Feixian Shao ◽

Xiujuan Li ◽

Zhenglei Yu ◽

...

Keyword(s):

Carbon Steel ◽

Stress Distribution ◽

Wear Behavior ◽

Coupling Effect ◽

Equivalent Stress ◽

Medium Carbon Steel ◽

Textured Surfaces ◽

Medium Carbon ◽

Biological Surface ◽

Starved Lubrication

Five densities of laser-ablated micro-pits were fabricated onto medium-carbon steel surfaces based on the coupling effect of the biological surface. The effects of the surface textures on the wear behavior were investigated by sliding wear tests under starved lubrication. The results show that compared with the smooth sample, the biomimetic samples could effectively reduce friction and wear, and the tribological performance of the textured surfaces is closely related to the density of the bionic units. The equivalent stress distribution of the specimens was simulated by the finite element method. A uniform stress distribution is beneficial for effectively reducing the generation of wear cracks.

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