scholarly journals Effect of minimum quantity lubrication strategies on tribological study of simulated machining operation

2019 ◽  
Vol 20 (6) ◽  
pp. 624 ◽  
Author(s):  
Sana Werda ◽  
Arnaud Duchosal ◽  
Guénhaël Le Quilliec ◽  
Antoine Morandeau ◽  
René Leroy
Keyword(s):  
Coefficient Of Friction ◽  
Minimum Quantity Lubrication ◽  
Front Face ◽  
Rake Face ◽  
Steel Cylinder ◽  
Tribological Tests ◽  
Flank Face ◽  
Apparent Coefficient Of Friction ◽  
Frictional Behaviour ◽  
Cooling Ability

The main aim of this paper was to reproduce the frictional behaviour that occurred in milling with a pin-on-cylinder system. Three different tribological tests were conducted reproducing friction phenomenon that happened in three machining conditions: (i) dry rubbing, representing the dry machining condition, (ii) MQL applied to front face rubbing which was similar to milling with MQL applied on the insert rake face and (iii) MQL applied to rear end rubbing which was similar to milling with MQL applied on flank face. Tribological tests were carried out with coated tungsten carbide pins rubbing on X100CrMoV5 steel cylinder. Apparent coefficient of friction, adhesion area and heat flux transmitted to the pin were analysed. It has been shown that MQL rear end rubbing provided a lower adhesion area and lower apparent coefficient of friction than with MQL front face rubbing. Furthermore, MQL rear end rubbing resulted in a greater cooling ability. These findings helped to explain why better results were obtained with MQL flank face lubrication in milling compared to MQL rake face lubrication.

Additiv gefertigtes Drehhaltersystem*/Additively manufactured turning tool system - Impact of application strategy of cryogenic carbon dioxide snow on thermomechanical tool load

2017 ◽  
Vol 107 (06) ◽  
pp. 420-425
Author(s):  
T. Heep ◽  
E. Prof. Abele
Keyword(s):  
Carbon Dioxide ◽  
Rake Face ◽  
Turning Operations ◽  
Research Activities ◽  
Flank Face ◽  
Face Cooling ◽  
System Impact

Das große Potenzial kryogener CO2-Schneekühlung beim Drehen schwer zerspanbarer Materialien wurde von verschiedenen Experten bereits nachgewiesen. Im Rahmen dieser Untersuchung wird ein additiv gefertigter Drehhalter mit erhöhter Funktionalität und modularer Bauweise vorgestellt. Dieser erlaubt neben der simultanen span- und freiflächenseitigen Kühlung mit CO2-Schnee erstmals die spanflächenseitige Applikation kryogener Mehrstoffkühlung beim Drehen.   The potential of cryogenic CO2-cooling in machining of difficult-to-cut materials has been confirmed by numerous research activities. This paper introduces an additively manufactured turning tool system that features enhanced functionality and modularity. Despite enabling the simultaneous cooling of a cutting edge’s rake and flank face using CO2-snow, it is the first system that allows for cryogenic multi-component rake face cooling in turning operations.

scholarly journals Resistance of PVD Coatings to Erosive and Wear Processes: A Review

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 921
Author(s):  
Alicja Krella
Keyword(s):  
Wear Rate ◽  
Solid Particle ◽  
Coefficient Of Friction ◽  
Cavitation Erosion ◽  
Solid Particles ◽  
Solid Particle Erosion ◽  
Pvd Coatings ◽  
Particle Erosion ◽  
Tribological Tests ◽  
Hydraulic Machines

Due to the increasing maintenance costs of hydraulic machines related to the damages caused by cavitation erosion and/or erosion of solid particles, as well as in tribological connections, surface protection of these components is very important. Up to now, numerous investigations of resistance of coatings, mainly nitride coatings, such as CrN, TiN, TiCN, (Ti,Cr)N coatings and multilayer TiN/Ti, ZrN/CrN and TN/(Ti,Al)N coatings, produced by physical vapor deposition (PVD) method using different techniques of deposition, such as magnetron sputtering, arc evaporation or ion plating, to cavitation erosion, solid particle erosion and wear have been made. The results of these investigations, degradation processes and main test devices used are presented in this paper. An effect of deposition of mono- and multi-layer PVD coatings on duration of incubation period, cumulative weight loss and erosion rate, as well as on wear rate and coefficient of friction in tribological tests is discussed. It is shown that PVD coating does not always provide extended incubation time and/or improved resistance to mentioned types of damage. The influence of structure, hardness, residence to plastic deformation and stresses in the coatings on erosion and wear resistance is discussed. In the case of cavitation erosion and solid particle erosion, a limit value of the ratio of hardness (H) to Young’s modulus (E) exists at which the best resistance is gained. In the case of tribological tests, the higher the H/E ratio and the lower the coefficient of friction, the lower the wear rate, but there are also many exceptions.

scholarly journals Additive surface texturing of cutting tools using pulsed laser implantation with hard ceramic particles

2020 ◽  
Vol 14 (5-6) ◽  
pp. 733-742
Author(s):  
S. Böhm ◽  
A. Ahsan ◽  
J. Kröger ◽  
J. Witte
Keyword(s):  
Flank Wear ◽  
Cutting Tools ◽  
Surface Texturing ◽  
Pulsed Laser ◽  
Ductile Cast Iron ◽  
Surface Structures ◽  
Rake Face ◽  
Dry Cutting ◽  
Ceramic Particles ◽  
Flank Face

AbstractIn recent years surface texturing of the cutting tools has proved to improve tribological characteristics at tool/chip and tool/workpiece interface and help to reduce cutting and feed forces as well as tool wear. Most, if not all, of the studies have focused on subtractively made textures whereby the material is removed from the surface. This study investigates the performance of additively made surface structures whereby hard ceramic particles are dispersed in the form of dome shaped textures on the surface of the cutting tools using solid state millisecond pulsed laser (pulsed laser implantation). Dry cutting tests were performed on ductile cast iron. The results show a greater reduction of process forces with implantation of flank face as compared to rake face. Both cutting and feed forces were reduced by 10% compared to the non-structured tool. In addition, the tool life increased by a factor of 3 whereas the average flank wear reduced by as much as 80% and cutting edge rounding by up to 60%.

The friction of clean crystal surfaces

1966 ◽  
Vol 295 (1442) ◽  
pp. 233-243 ◽  
Keyword(s):  
Coefficient Of Friction ◽  
High Surface ◽  
High Vacuum ◽  
Surface Films ◽  
Surface Adhesion ◽  
Crystal Surfaces ◽  
Deformation And Fracture ◽  
The Coefficient Of Friction ◽  
Molecular Layers ◽  
Frictional Behaviour

A study is made of the frictional behaviour of crystals (diamond, magnesium oxide, sapphire) sliding on themselves in high vacuum (10 -10 torr). The surface films normally present on these crystals are very tenacious but they may be worn away by repeated sliding in the same track. Under these conditions the friction of the clean crystals may increase by a factor of ten so that the coefficient of friction may rise to μ ≈ 1. The frictional rise is limited because of the elastic and brittle behaviour of the contact regions. Under these conditions subsurface deformation and fracture of the crystal occurs and this, combined with the high surface adhesion, causes pronounced wear. Adsorption of a few molecular layers of gas can again reduce the friction to a low value. The results are relevant to the operation of bearings and to the wear of surfaces in space.

Experimental Study of Tool Wear during Quasi High Speed Turning Titanium Alloy with Large Cutting Depth

2014 ◽  
Vol 800-801 ◽  
pp. 548-552
Author(s):  
Li Fu Xu ◽  
Wei Liang Dong ◽  
Shu Tao Huang ◽  
Bao Lin Dai
Keyword(s):  
Experimental Data ◽  
Titanium Alloy ◽  
High Speed ◽  
Flank Wear ◽  
Rake Face ◽  
Cutting Depth ◽  
Tool Flank Wear ◽  
High Speed Turning ◽  
Flank Face ◽  
Cutting Speeds

The wear morphology of rake face and flank face of tool is investigated by turning titanium alloy TC4 with CBN solid tool. It has been observed that the main wear form of rake face and flank face of tool is groove wear. The relation between tool flank wear and cutting speeds, feed rate, and cutting depth obtained from experimental data is given.

Apparent Coefficient of Friction of Wheat on Denim

2017 ◽  
Vol 23 (3) ◽  
pp. 175-181 ◽  
Author(s):  
Charles V. Schwab
Keyword(s):  
Standard Deviation ◽  
Moisture Content ◽  
Bulk Density ◽  
Coefficient Of Friction ◽  
Current Understanding ◽  
Farm Safety ◽  
The Coefficient Of Friction ◽  
Denim Fabric ◽  
Apparent Coefficient Of Friction

Abstract. Calculation of the extraction force for a grain entrapment victim requires a coefficient of friction between the grain and the surface of the victim. Because denim is a common fabric for the work clothes that cover entrapment victims, the coefficient of friction between grain and denim becomes necessary. The purpose of this research was to calculate the apparent coefficient of friction of wheat on denim fabric using a proven procedure. The expectation is to improve the current understanding of conditions that influence extraction forces for victims buried in wheat. The apparent coefficient of friction of wheat on denim fabric was calculated to be 0.167 with a standard deviation of ±0.013. The wheat had a moisture content of 10.7% (w.b.) and bulk density of 778.5 kg m-3. The apparent coefficient of friction of wheat on denim was not significantly affected by pull speeds of 0.004, 0.008, and 0.021 mm s-1 nor normal grain pressures of 3.2, 4.8, 6.3, 7.9, and 11.1 kPa. This is a beginning of understanding the conditions that influence the extraction forces for grain entrapment victims. Keywords: Farm safety, Grain entrapment, Grain rescue, Grain extraction.

scholarly journals Research on the Cutting Principle and Tool Design of Gear Skiving Based on the Theory of Conjugate Surface

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Peng Wang ◽  
Jingcai Li ◽  
Lin Han
Keyword(s):  
Mathematical Model ◽  
Design Principle ◽  
Design Method ◽  
Tool Design ◽  
Theoretical Research ◽  
Machining Accuracy ◽  
Rake Face ◽  
Key Factors ◽  
Flank Face ◽  
The Mathematical Model

Tool design is one of the key factors that restrict the development of gear skiving technology since the design principle does not correspond to the cutting principle. The existing skiving tool cannot achieve ideal machining accuracy and reasonable cutting angles. In view of this, some research has been done in this paper. Firstly, the skiving principle is investigated essentially according to the skiving motions. Then, the principle of tool design is analyzed based on the theory of conjugate surface, and a new tool design method is proposed to match the skiving principle. For this, all the skiving patterns for various kinds of workpieces are enumerated and summarized to abstract a normalized skiving model. Based on this, the mathematical model of the conjugate surface is then derived to lay the foundation for tool design. Then, the design methods of cutting edge, rake face, and flank face are proposed. An example is presented at last, and the cutting simulation is conducted. The result proves that the proposed methods are correct and valid. The theoretical research in this paper could promote the improvement of skiving tools.

Research and Development of Four Axis Linkage Grinding Simulation System of Ball-Nose End Mill

2010 ◽  
Vol 443 ◽  
pp. 314-317
Author(s):  
Lin He ◽  
Xian Feng Zhao ◽  
Hong Yan Shi ◽  
Jun Wang
Keyword(s):  
Simulation System ◽  
Rake Face ◽  
End Mill ◽  
Ball End Mill ◽  
Nc Programming ◽  
Solid Models ◽  
Flank Face ◽  
The Mathematical Model ◽  
Face Grinding ◽  
Grinding Simulation

The four axis linkage grinding simulation system of ball-nose end mill has be developed based on the mathematical model of four axis linkage grinding through establishing ball-nose end mill's parametrical database, constructing ball-nose end mill’s and grinding wheel's solid models in Solidworks, simulating the grinding processes of the rake face and flank face of ball-nose end mill based on Boolean operation, and automatic NC programming of rake face and flank face grinding. The results show the grinding simulation system can be used to manufacture ball end mill.

scholarly journals The Influence of Surface Texturing on the Frictional Behaviour in Starved Lubricated Parallel Sliding Contacts

Lubricants ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 68 ◽  
Author(s):  
Bijani ◽  
Deladi ◽  
Rooij ◽  
Schipper
Keyword(s):  
Coefficient Of Friction ◽  
Surface Texturing ◽  
Geometrical Parameters ◽  
Textured Surfaces ◽  
Tribological Behaviour ◽  
Sliding Contacts ◽  
Cavitation Effect ◽  
The Coefficient Of Friction ◽  
Starved Lubrication ◽  
Frictional Behaviour

Starvation occurs when the lubricated contact uses up the lubricant supply, and there is not enough lubricant in the contact to support the separation between solid surfaces. On the other hand, the use of textures on surfaces in lubricated contacts can result in a higher film thickness. In addition, a modification of the surface’s geometrical parameters can benefit the tribological behaviour of the contacts. In this article, for parallel sliding surfaces in starved lubricated conditions, the effect of surface texturing upon the coefficient of friction is investigated. It is shown that surface texturing may improve film formation under the conditions of starvation, and as a result, the frictional behaviour of the parallel sliding contact. Furthermore, the effect of starved lubrication on textured surfaces with different patterns in the presence of a cavitation effect, and its influence on frictional behaviour, is investigated. It is shown that surface texturing can reduce the coefficient of friction, and that under certain conditions, the texturing parameter could have an influence on the frictional behaviour of parallel sliding contacts in the starved lubrication regime.

Effect of surface structure, composition and texture on friction under boundary conditions

1952 ◽  
Vol 212 (1111) ◽  
pp. 508-512
Keyword(s):  
Oxide Film ◽  
Boundary Conditions ◽  
Coefficient Of Friction ◽  
Substrate Material ◽  
Pure Aluminium ◽  
Surface Layers ◽  
The Coefficient Of Friction ◽  
The Difference ◽  
Frictional Behaviour ◽  
Effect Of Surface

The coefficient of friction of surfaces lubricated under boundary conditions may be profoundly affected by such factors as the degree of working of the substrate material, the nature of the oxide film and the degree of roughness of the surface. Experiments are described wherein the frictional behaviour of surfaces of stainless steel specimens prepared in various ways was compared. The worked surface layers in these particular experiments appear to increase the value of the coefficient of friction, but the effect of surface texture is of predominant importance. The effect of different oxide films is best illustrated by reference to pure aluminium, the surface of which has been oxidized under different environmental conditions. The constitution of the oxide film formed is modified with a consequent effect on boundary friction. When the friction of rough and smooth surfaces is compared, the difference in behaviour appears to be qualitative rather than quantitative.

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