Tribological studies of unpolished laser surface textures under starved lubrication conditions for use in air-conditioning and refrigeration compressors

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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Tribological effects of laser surface texturing and residual stress

Industrial Lubrication and Tribology ◽

10.1108/ilt-11-2016-0282 ◽

2018 ◽

Vol 70 (1) ◽

pp. 126-132 ◽

Cited By ~ 7

Author(s):

Shuwen Wang ◽

Feiyan Yan ◽

Ao Chen

Keyword(s):

Residual Stress ◽

Wear Resistance ◽

Friction And Wear ◽

Surface Texturing ◽

Laser Surface ◽

Friction Reduction ◽

Laser Surface Texturing ◽

Wear Testing ◽

Content Type ◽

Surface Textures

Purpose The purpose of this paper is to investigate the tribological effects of laser surface texturing (LST) and residual stress on functional surfaces. Design/methodology/approach Three different surface textures (circular dimple, elliptical dimple and groove) with two different textured area ratios (10 and 20 per cent) are designed and fabricated by a Picosecond Nd YAG Laser machine. The friction and wear performance of textured specimens is tested using a UMT-2 friction and wear testing machine in mixed lubrication. Findings Test results show that elliptical dimples exhibit the best performance in wear resistance, circular dimples in friction reduction and grooves in stabilization of friction. The surfaces with larger textured area density exhibit better performance in both friction reduction and wear resistance. The improved performance of LST is the coupled effect of surface texture and residual stress. Originality/value The findings of this study may provide guidance for optimal design of functional surface textures in reciprocating sliding contacts under mixed or hydrodynamic lubrication, which can be used in automotive and other industrial applications.

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Effectiveness of multi-shape laser surface texturing in the reduction of friction under lubrication regime

Industrial Lubrication and Tribology ◽

10.1108/ilt-03-2015-0041 ◽

2016 ◽

Vol 68 (1) ◽

pp. 116-124 ◽

Cited By ~ 11

Author(s):

Dawit Zenebe Segu ◽

Pyung Hwang

Keyword(s):

Hydrodynamic Lubrication ◽

Surface Texturing ◽

Laser Surface ◽

Laser Surface Texturing ◽

Textured Surface ◽

Content Type ◽

Laser Ablation Process ◽

Specific Formula ◽

Steel Surfaces ◽

Lubrication Conditions

Purpose – The purpose of this paper is to investigate and discuss the effect of multi-shape laser surface texturing (LST) steel surfaces on tribological performance. Design/methodology/approach – The textured surface with some specific formula arrays was fabricated by laser ablation process by combining patterns of circles and triangles, circles and squares and circles and ellipses. The tribological test was performed by a flat-on-flat tribometer under dry and lubrication conditions, and results were compared with that of untextured surface. Findings – The results showed that the textured surface had better friction coefficient performance than the untextured surface due to hydrodynamic lubrication effect. Through an increase in sliding speed, the beneficial effect of LST performance was achieved under dry and lubrication conditions. Originality/value – This paper develops multi-shape LST steel surfaces for improving the friction and wear performance under dry and lubrication conditions.

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Numerical Simulation of the Influence of the Bulges around Laser Surface Textures on the Tribological Performance

Tribology Transactions ◽

10.1080/10402004.2013.819956 ◽

2013 ◽

Vol 56 (6) ◽

pp. 1011-1018 ◽

Cited By ~ 11

Author(s):

Jian Li ◽

Xiao Wang

Keyword(s):

Numerical Simulation ◽

Tribological Performance ◽

Laser Surface ◽

Surface Textures

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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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