Lubricating Performance of Residual Zinc Phosphate Coating on Forged Specimen in Bowden-Leben Sliding Test

2018 ◽  
Vol 767 ◽  
pp. 124-130 ◽  
Author(s):  
Osamu Kada ◽  
Zhi Gang Wang
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Zinc Phosphate ◽  
Cold Forging ◽  
Phosphate Coating ◽  
Specimen Temperature ◽  
Tool Surface ◽  
Residual Thickness ◽  
Surface Expansion ◽  
Sliding Test

The lubricating performance of the zinc phosphate coating employed generally in cold forging is evaluated with Bowden-Leben sliding test by changing friction conditions such as the coating thickness, specimen temperature, the tool surface roughness, contact pressure and sliding speed. A specimen for the friction test is prepared from the inner surface of an extruded square cup and the residual thickness of the lubrication coating on the specimen is controlled by using the surface expansion in forward extrusion of the cup. Experimental results showed that the specimen temperature has the strongest influence on the friction coefficient. With an increase of the specimen temperature, the friction coefficient gradually decreases until 473K, and then increases sharply. With an increase of the tool surface roughness, the friction coefficient increases slightly. Friction coefficient is formulated as a function of the specimen temperature and the tool surface roughness. The anti-galling ability of the coating is affected by the residual thickness of lubrication coating, the specimen temperature and the tool surface roughness.

Development of Upsetting-Extrusion Type Tribometer for Evaluating Lubrication Coating Performance in Cold Forging

2014 ◽  
Vol 966-967 ◽  
pp. 281-289 ◽  
Author(s):  
Zhi Gang Wang ◽  
Shinobu Komiyama ◽  
Yasuharu Yoshikawa
Keyword(s):  
Zinc Phosphate ◽  
Side Surface ◽  
Extrusion Process ◽  
Peak Height ◽  
Expansion Ratio ◽  
Cold Forging ◽  
Maximum Height ◽  
Phosphate Coating ◽  
Multi Stage ◽  
Surface Expansion

A new upsetting-extrusion type tribometer is developed to investigate the performance of a lubrication coating on the side surface of a billet in multi-stage cold forging. In this tribometer, the lubrication coating on the billet surface is first destroyed by the upsetting process and then evaluated by the extrusion process. The frictional shear factor of the lubrication coating is obtained by plotting the measured extrusion load and the position after the extrusion of a centerline drawn on the billet in advance on the calibration curve obtained by FEM. Experimental results using a zinc phosphate coating and a dry in-place type coating showed that the reduced peak height Rpk is more appropriate than the maximum height Rz to express the effect of the surface roughness of tool on galling generation. When no galling occurs, the frictional shear factor hardly varies with the type of the lubrication coating and the surface expansion ratio. The anti-galling ability of the dry in-place type coating is greatly improved by a two-stage shot blast before the lubrication coating and reaches a level better than the zinc phosphate coating.

Switchable Friction Coefficient on Shape Memory Photonic Crystals

MRS Advances ◽  
2020 ◽  
Vol 5 (14-15) ◽  
pp. 757-763
Author(s):  
Yifan Zhang ◽  
Xingyi Lyu ◽  
Yongliang Ni ◽  
Diyang Li ◽  
Sin-Yen Leo ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Photonic Crystal ◽  
Friction Coefficient ◽  
Photonic Crystals ◽  
Shape Memory ◽  
Intelligent Control ◽  
Surface Friction ◽  
Soft Robotics ◽  
Sliding Test ◽  
Sensor Interfaces

ABSTRACTIntelligent control of friction and adhesion has attracted much attention for use in soft robotics, human-sensor interfaces, and bionics. Here we introduce a shape memory photonic crystal (SMPC) polymer that can be programmed and recovered by solvent to realize switchable surface friction. Micro sliding test show that the friction coefficient on this SMPC in the programmed and recovered state can vary by three times. We also show that the mechanism behind this switchable friction coefficient is the surface roughness related adhesion.

Seizure Strength Improvement for Phosphate-Stearate Coatings Involved in Cold Forging of Steel

1992 ◽  
Vol 114 (2) ◽  
pp. 248-252 ◽  
Author(s):  
Ph. Hivart ◽  
J. P. Bricout ◽  
J. Oudin ◽  
J. Y. Dauphin
Keyword(s):  
Mechanical Strength ◽  
Zinc Phosphate ◽  
Zinc Stearate ◽  
Cold Forging ◽  
Attractive Alternative ◽  
Phosphate Coating ◽  
Test Results ◽  
Phosphate Bonding ◽  
Strength Improvement ◽  
Tangential Friction

A seizure test particularly well suited to evaluate the mechanical strength of phosphate-stearate coatings has been developed. Test results, including tangential friction force and time at the onset of seizure, are related to the effective phosphate bonding and to lubricant reactive effects. It is shown that seizure is delayed if the phosphate coating is annealed at 500°C just before soaping. The γ-Zn3 (PO4)2 formation which occurs with a decrease in volume induces cracking along hopeite needles and causes an increase in reactive surface for soaping and, therefore, an increase in the quantity of zinc phosphate converted into zinc stearate. Improvement of the phosphate coating by annealing at 500°C before soaping may be an attractive alternative to the use of molybdenum disulfide lubricants.

scholarly journals Effect of Tool Surface Roughness on Friction Behaviorof Lubricant Coating in Cold Forging

2010 ◽  
Vol 51 (591) ◽  
pp. 342-347 ◽  
Author(s):  
Shinobu KOMIYAMA ◽  
Zhigang WANG ◽  
Ryuichi TOKUNAGA ◽  
Yuichi YAMAOKA
Keyword(s):  
Surface Roughness ◽  
Cold Forging ◽  
Lubricant Coating ◽  
Tool Surface

Lubrication efficiency of vegetable oil nano-lubricants and solid powder lubricants

2018 ◽  
Vol 233 (7) ◽  
pp. 1384-1392
Author(s):  
Peyman Mashhadi Keshtiban ◽  
Saeid Sheydaei Govarchin Ghaleh ◽  
Vali Alimirzaloo
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Environmental Risk ◽  
High Surface ◽  
High Surface Area ◽  
Cold Forging ◽  
Forging Process ◽  
Oil Reserves ◽  
Friction Calibration

Reducing crude oil reserves and also environmental pollution caused by its excessive use has led to numerous researches to find alternatives to petroleum-based oils. Thus, owing to lower pollution and higher lubrication efficiency, the use of vegetable base lubricants has been widely considered. Due to the unique properties of different nanoparticles such as sphericality and high surface area besides low environmental risk, the subjected nanoparticles can be applied as additives to the base lubricants and create optimal tribological properties. In this study, in order to improve the lubricating efficiency of vegetable base lubricants, SiO2nanoparticles with different weight concentrations were used in the cold forging process of aluminum alloy. Then, the lubrication proficiency of both nano-lubricants and conventional solid powder lubricants in the forging industry was evaluated. Friction coefficient was determined by standard compression test and friction calibration curves. In order to evaluate the lubricants’ efficiency, two key parameters, namely shear friction coefficient and surface roughness have been considered. Experimental results showed that the presence of SiO2nanoparticles in the base lubricants significantly increased the lubrication efficiency of the base lubricants and notably reduced both the friction coefficient and surface roughness.

Development of Upsetting-Extrusion Type Tribometer for Evaluating Lubrication Coating Performance in Cold Forging

2013 ◽  
Vol 554-557 ◽  
pp. 833-843 ◽  
Author(s):  
Zhi Gang Wang ◽  
Shinobu Komiyama ◽  
Yasuharu Yoshikawa
Keyword(s):  
Zinc Phosphate ◽  
Side Surface ◽  
Extrusion Process ◽  
Peak Height ◽  
Expansion Ratio ◽  
Cold Forging ◽  
Maximum Height ◽  
Phosphate Coating ◽  
Free Expansion ◽  
Multi Stage

A new upsetting-extrusion type tribometer has been developed to investigate the performance of the lubrication coating on the side surface of a billet in the multi-stage cold forging. In this tribometer, the lubrication coating is first destroyed by the upsetting process due to the free expansion of the billet surface and then evaluated by the extrusion process. The frictional shear factor of the lubrication coating is obtained by plotting the measured extrusion load and the position after the extrusion of a centerline drawn on the billet in advance on the calibration curve obtained by FEM. Experimental results using a zinc phosphate coating and a dry in-place type coating showed that the reduced peak height Rpk is more appropriate than the maximum height Rz to express the effect of the surface roughness of tool on galling generation. When no galling occurs, the frictional shear factor hardly varies with the type of the lubrication coating and the surface expansion ratio. The anti-galling ability of the dry in-place type coating is greatly improved by a two-stage shot blast before the lubrication coating and reaches a level better than the zinc phosphate coating.

Influence of surface roughness, friction coefficient, and wrap angle on clinching joint strength and its correlation with belt friction phenomenon

2021 ◽  
pp. 135065012110253
Author(s):  
Santosh Kumar ◽  
Vimal Edachery ◽  
Swamybabu Velpula ◽  
Avinash Govindaraju ◽  
Sounak K. Choudhury ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Joint Strength ◽  
Joint Interface ◽  
Cross Sectional ◽  
Lap Shear ◽  
Mathematical Correlation ◽  
Mechanical Clinching ◽  
Wrap Angle

Clinching is an economical sheet joining technique that does not require any consumables. Besides, after its usage, the joints can be recycled without much difficulty, making clinching one of the most sustainable and eco-friendly manufacturing processes and a topic of high research potential. In this work, the influence of surface roughness on the load-bearing capacity (strength) of joints made by the mechanical clinching method in cross-tensile and lap-shear configuration is explored. Additionally, a correlating mathematical model is established between the joint strength and its surface parameters, namely, friction coefficient and wrap angle, based on the belt friction phenomenon. This correlation also explains the generally observed higher strength in lap-shear configuration compared to cross-tensile in clinching joints. From the mathematical correlation, through friction by increasing the average surface roughness, it is possible to increase the strength of the joint. The quality of the thus produced joint is analyzed by cross-sectional examination and comparison with simulation results. Experimentally, it is shown that an increment of >50% in the joint strength is achieved in lap-shear configuration by modifying the surface roughness and increasing the friction coefficient at the joint interface. Further, the same surface modification does not significantly affect the strength in cross-tensile configuration.

Research on Modeling Method of Runway Frictional Coefficient Measuring Vehicle Based on Impedance Diagrams

2011 ◽  
Vol 214 ◽  
pp. 133-137 ◽  
Author(s):  
Xu Dong Shi ◽  
Shou Wen Shi ◽  
Lu Zhang ◽  
Jian Li Li
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Measurement Data ◽  
Frictional Coefficient ◽  
Modeling Method ◽  
Measuring System ◽  
Discrete Fourier Transformation ◽  
Measuring Error ◽  
Impedance Diagram ◽  
Airport Runway

Airport runway friction coefficient is an important parameter to evaluate the quality of runway which is usually measured by runway friction coefficient measuring vehicle. In order to reduce the airport runway friction coefficient measuring error which comes from runway vibration caused by road roughness and vehicle its own structural characteristics, an impedance diagram is used to model the suspending system and measuring system of the measuring vehicle. The power spectral density of pavement and inverse discrete Fourier transformation are introduced to model runway surface roughness as excitation input. The rationality of the stimulating established model is validated by comparing with an airport runway surface roughness measurement data. Runway friction coefficient measuring vehicle′s measuring error can be reduced and the measurement accuracy can be improved by using the impedance diagram modeling method.

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