Different Types Of Lubricants Research Articles

Effect of Various Parameters on Finishing of Inner Surfaces of Brass Tubes Using Magnetic Abrasive by RSM: A Study

With the increase of technology and the demand of industry the surface finish requirements are also increasing. Conventional echnologies like grinding and lapping etc. fail to finish some pieces such as pipes, complex shape tubes consisting of straight and bent sections up to desired accuracy. Magnetic Abrasive Finishing (MAF) is one of the a dvanced finishing methods, proposed to produce highly finished surfaces of brass340 pipes. In this research work the process, finishing characteristics and the principle of magnetic abrasive finishing of pipes using sintered magnetic abrasives are described. The sintered based of Al2O3 magnetic abrasives with iron particle of size 106 μm were used in this work. The Statistically designed experiments based on Taguchi methods show that weight of abrasive, Revolutions per minute (rpm), finishing time and type of lubricant which have significant effect on the surface roughness obtained. The effects of lubricants on surface finish are also analyzed in this work by using different types of lubricants. It is noticed that the surface finish was affected by the change of type of lubricant and the internal surface finish of pipes were analyzed in terms of percent improvement in surface finish (PISF) and using Response Surface Methodology (RSM). The obtained maximum PISF was 60% by using toothpaste as a lubricant and minimum surface r oughness w as 0 .126 μ m R a. T he improvement in surface finish was further validated using RRay Diffraction (XRD) technique.

Wear Characterization of Aluminum Lubricated with Palm Olein at Different Normal Load

The pin-on-disk tester is a method used for investigating wear. The sliding mechanism between the pin and the disc experimentally creates wear. In this paper, the wear characteristics of an aluminium pin sliding on an SKD11 disc lubricated with double fraction palm olein were investigated. The pin was made from pure aluminum A1100. The results were compared with those of tests in which the disc was lubricated with commercial hydraulic oil. In both sets of experimental conditions, the normal load varied from 4 to 10 kg. Rotational speed was set to 1200 rpm. From this study, it was found that different types of lubricant affect the wear progression and friction coefficient during a sliding movement. The wear progression and friction coefficient depend also on the load applied, surface roughness, pressure applied and contact surface area.

Angstrom Scale Wear of the Air-Bearing Sliders in Hard Disk Drives

We utilize thermal fly-height control (TFC) technology to perform in situ measurements of carbon overcoat wear at the angstrom level at the read–write area of magnetic recording heads. We also study the durability of the molecularly thin lubricated disk surface. Experimental findings reveal a linear relationship between the quantified carbon wear depth on the flying head versus the head–disk contact level produced by the TFC power. It is demonstrated that this method can serve as a measurement and probing technique of wear resistance for different types of lubricants. Lubricants possessing more polar hydroxyl end-groups and less mobility tend to show a superior surface stability under head–disk contacts, but raise concerns on head carbon overcoat wear.

Effect of Surface Roughness of Pure Aluminium A1100 on the Cold Work Extrusion by Using Different Angles of Taper Die

The study presented in this paper is focused on the effect of surfaces roughness of pure aluminium A1100 on the cold work extrusion process by three different angles of taper die. Different angles of taper die will affect the surface roughness of the workpiece. To protect the surface and to reduce friction, lubricants are often used in extrusion process [1]. Different lubricants may have different optimum taper die angle that are suitable to be applied. Two types of materials used in this experiment are steel SKD 11 for taper die and aluminium A1100 for workpiece and different angles applied are 30o, 45o, and 60o. Moreover, with respect to each angle, three different types of lubricants were used which are Daphne Draw S Series, Palm Olein, and EFB bio oil. The Universal Testing Machine and Surface Roughness Tester were used in this experiment. The result obtained from the experiment shows that at 30o of taper die angle were producing the smooth product surfaces for each lubricant and Daphne Draw S Series could reduce the surface roughness compared to other lubricant test.

Impaction of suction catheter during paediatric anaesthesia

We read with interest articles describing impaction of a gum-elastic bougie in a tracheal tube (TT) and the effects of different types of lubrication on the force needed to retract a stylet from a TT 1, 2. We report a case of catheter impaction during tracheal suction under general anaesthesia. A 6-year-old weighing 16 kg was scheduled for right nephrectomy under general anaesthesia. All routine investigations were within normal limits and physical examination including airway assessment was unremarkable. Laryngoscopy revealed a Cormack and Lehane grade-3 view and the trachea was intubated with a 5-mm cuffed TT after external laryngeal manipulation. The child was positioned in the left lateral decubitus position. Approximately 40 min after intubation, audible crepitations were heard from the TT. A 10-FG PVC suction catheter was introduced into the TT to clear presumed secretions. Insertion was easy but whilst being withdrawn, the suction catheter appeared to become lodged within the TT's lumen. Attempts to remove the catheter proved futile despite gentle traction and rotation of the catheter. Before desaturation occurred, the TT cuff was deflated and the TT was removed with the suction catheter in situ. The lungs were ventilated via a facemask but several attempts at re-intubation failed because obtaining a view of the vocal cords was impossible. Finally the airway was secured with a size-2 LMA. Thereafter, maintenance of and recovery from anaesthesia proceeded uneventfully. No visible abnormality was identified in the TT or suction catheter. Similar impaction has been attributed to an increase in surface tension due to small amounts of condensed vapour between the outer surface of the suction catheter and the inner aspect of the TT's anterior wall 3. Interestingly, use of water as a lubricant to aid easier passage of a suction catheter through the TT has also been advocated. We believe that paediatric TTs, with a smaller lumen and sharper curve, exaggerates the friction between the two and may more readily lead to impaction of the catheter. Selection of an appropriately sized catheter for suctioning is important. The French gauge of the suction catheter should be no more than one and half times the size of the TT's internal diameter in mm. We also believe that the suction catheter should be lubricated, or another option is to use a siliconised suction catheter.

Molecular Dynamics Simulation for Lubricant Shear Properties During Heating

This paper discusses the shear properties of ultra-thin lubricant film on hard disk media during heating. A molecular dynamics method is used on four different types of lubricant to better understand the phenomena on the atomic scale. We investigate the shear mobility of lubricant for each temperature between 30°C and 300°C, assuming there is an air shear-induced migration on a carbon overcoat. The simulation results show that a thick lubricant film has a mobile and restricted layer, while a thin film which thickness is less than 1 nm , increases the slippage at lubricant/overcoat interface. At a high temperature, a lubricant with a flexible main chain tends to have a higher level of mobility. The difference in lubricant shear property is closely related to the flexibility of main chain and the amount of functional groups of lubricant which can affect the shear viscosity and adhesion to the carbon overcoat.

Evaluation of Stamping Lubricants in Forming Galvannealed Steels for Industrial Application

Lubrication is one of the process variables that affect the quality of stamping sheet materials. Using a good lubricant can significantly reduce scrap rate and/or improve the quality of stamping. In this study, different types of lubricants were evaluated using strip draw test (SDT) and deep draw test (DDT) for stamping of galvannealed steel sheets. Finite element (FE) simulations were carried out to determine the coefficient of friction at tool-work piece interface during deep drawing under different lubrication conditions and blank holder forces. Flow stress data of materials under biaxial load which are used in FE simulations are obtained by viscous pressure bulge tests. SDT was used as a preliminary test to evaluate the relative performance of the lubricants. Lubricants that showed good performance in this test were tested using DDT. Dimensions of the formed strips and cups and the maximum applicable blank holder force to draw parts without fracturing were the criteria used for evaluation of lubricants in both tests. In general, it was possible to form cups with higher blank holder force when synthetic/water-based lubricants were applied to the sheet. In conclusion, evaluated synthetic/water-based lubricants had better lubricity than petroleum-based lubricants.

Effects of phosphorus on friction behaviour in wet clutch systems: A comparison of various coatings

This paper presents the investigation of effects of phosphorus-containing coatings on the friction behaviour. Three types of technologically fabricated coatings are investigated: zinc phosphate, iron phosphate, and a third the composition of which is still confidential as it is being patented. For the description of the composition and the properties of these coatings, scanning electron microscopy, energy dispersive X-ray analysis, and electron backscattered diffraction are used among other methods. Friction behaviour is characterized by a disc-on-disc tribometer, in which coated steel discs rotate against so-called paper friction discs under lubricated conditions. Tests are carried out with two different types of lubricants and at two temperatures. The disc-on-disc tests show the influence of coatings on the level and stability of the coefficient of friction (the occurrence of stick—slip or vibrations). Results show that phosphorus-containing coatings reduce or – in certain cases – even prevent the occurrence of stick—slip. Therefore, one focus of the discussion is the investigation of layers formed during tribological tests. For detailed chemical information of the surface, selected systems are also characterized by X-ray photoelectron spectroscopy. Differences in the chemical state of otherwise equal zinc phosphate coatings can explain differences in the experimental results.

Experimental evaluation of lubricant influence on residual stress in turning operations

In cutting operations it is very important to know the surface residual stresses on the final part since they affect functional aspects of the workpiece such as: fatigue life, resistance to corrosion and wear resistance. Recent studies showed that the development of tensile or compressive stresses is mainly influenced by the cutting parameters, tool geometry and the nature of the worked material. This paper reports the results obtained when studying the influence of different types of lubrication and of some process parameters (i.e. the tool nose radius and the feed rate) on the workpiece residual stresses in cutting operation. The experimental tests were carried out turning AISI 1045 steel bars. The maximum and minimum principal residual stresses on the surface were identified measuring the stresses along three different directions (0°/+60°/−60° with respect to the bar axis) using the X-ray diffraction technique. In addition, a 3D FEM model of the process was developed with the aim of proving the ability of such a model in predicting the surface residual stresses.

Solid-state interaction study on the captopril/lubricants systems accelerated by grinding process

To better study possible solid-state interactions between captopril (CAP) and different types of lubricants at the surface, grinding process was applied to enhance the probability of reaction. Grinding process was carried out for 5 min at room temperature under 32±5% or 80±5% relative humidity (RH) condition. The physical and ground mixtures of CAP and each lubricant (weight ratio: 1:1) were examined by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) microspectroscopy equipped with or without micro hot stage. The results indicate that CAP did not interact with talc, Precirol or stearic acid even if the grinding process was applied. However, a mixture of CAP and each metallic stearate before and after grinding exhibited a different behavior. Although there was a lack of interaction between CAP and sodium stearate in the course of grinding process, this process could induce the trans–cis isomerization of CAP in the CAP–sodium stearate ground mixture. No evidence was observed to show the solid-state interaction between CAP and monoaluminum stearate, but the grinding process seemed to accelerate the solid-state interaction of CAP with magnesium stearate (MgSt). The fact that solid-state interaction occurred between CAP and MgSt was proven by the shifting of the IR spectral peak of ν as (COO −) of stearate from 1578 to 1541 cm −1, due to interaction of the OH group in carboxylic acid structure of CAP with bridging coordination of the COO − group of MgSt via hydrogen bonding of water. The interaction occurred between CAP and MgSt was stopped at 60 °C, due to the dehydration of water from the ground mixture.

Relationship between physical structure and machinability of green compacts

The dependence of green machinability on compact density and strength was investigated for room temperature and warm compacted steel powder compacts containing two different types of lubricant. Brazilian disc compression tests were employed to determine green strength, while machinability was assessed in terms of response to drilling.For the room temperature compacted materials, it was found that high compact densities and strength were not, in most cases, associated with improvements in machinability. Furthermore, it was shown that lubrication (both type and quantity) and compaction pressure plays a critical role in determining the level of breakouts observed. In contrast, the use of warm compaction, in conjunction with specially designed lubricants, has been shown to be a suitable method of producing high density, high strength compacts while retaining good green machining characteristics. Mechanisms responsible for the observed behaviours of both the room temperature and warm compacted specimens have been forwarded in the present paper.

Lubrication of Aluminium Sheet Metal within the Automotive Industry

The production of automotive body parts and panels is a very complex process, starting with the raw materials and ending in the paint shop. Due to the fact that aluminium sheet metal has to be lubricated before forming, all of the following processes have to be considered. Lubricants, such as oils, dry-film lubricants or recently introduced hotmelts have to protect the material’s surface, reduce friction whilst drawing the panels and should not compromise further treatments [1]. Different types of lubricants show different characteristics. This difference is especially noticeable when comparing liquid and dry-film lubricants. As dry-film lubricants do not run off the blanks’ surface and are distributed homogeneously, they show different tribological properties compared to conventional liquid lubricants. The effect on friction of aluminium sheet metal is shown through several basic experiments [2, 3]. In addition, the paper shows the effect of further operations within the production chain. The advantages and disadvantages not only for drawing, but also for assembly lines and the painting process are described in this paper. Assembly issues are carried out on stability testings of riveted and clinched assemblies. These trials show how the assembly process is affected by different proceedings. The fact that every car body has to be completely free of grease before painting, signifies the necessity to get lubrication off the car body’s surface before painting. The interactions between lubrication and paint shop are shown on typical process parameters. Most typical characteristics considering bonding and riveting were tested out on a hood assembly of the current BMW 7-series. In addition to that, experiences made in the press shop at BMW’s Dingolfing plant were figured out and carried over to a long-term strategy of pre-lubrication of aluminium sheet metal. This includes adhesive compatibility as well as the above mentioned assembly process.

Application of Atomic Force Microscopy to the Study of Lubricant Additive Films

Constant force mode atomic force microscopy is used to examine the films formed on steel surfaces by three different types of lubricant additive. Work on molybdenum dithiocarbamate friction modifier additive solutions shows that this additive forms tiny domains of low friction on the high spots of rubbed surfaces. Complementary Raman surface analysis suggests that these domains represent crystallites of MoS2. Study of the reaction films formed by zinc dialkyldithiophosphate additives confirms the formation of pad-like structures by these additives on rubbed surfaces. Primary and secondary forms of the additive are shown to form films of different morphology and properties. Colloid probe atomic force microscopy has also been applied to study the boundary film-forming properties of functionalized viscosity modifier polymers. It is shown that these polymers can form viscous boundary films on rubbed surfaces which produce much lower friction than the corresponding, nonfunctionalised polymers. Overall it is suggested that atomic force microscopy can provide valuable information concerning the nature and properties of boundary films formed by lubricant additives especially when used in parallel with macro-scale friction and film thickness measurements.

Advanced lubrication technology for X-1P interaction with media carbon and Z-type lubricants

X-1P has been widely used as an additive to media PFPE lubricant since 1995. It is also reported that it can provide good HDI (Head-Disk Interface) protection at 0.5 nm thickness when used straight. Due to increased recording density and lower flying heights, the stress placed on the HDI will require improved lubricant/carbon interaction for X-1P. Bonding interaction is investigated using two techniques, the dip lubricant method and the vapor deposition technique. Comparison of “fresh” versus “air exposed” samples were made with the latter. With various deposition conditions, the PFPE lubricant and X-1P bonding was studied. By comparing different types of lubricants and solvents under the first technique, we observed that the lubricant and X-1P bonding interact with each other. With the second technique we observed differences between “fresh” and “air exposed” samples, indicating that adsorbed species on the carbon surface compete with X-1P and lubricant bonding.

Wear Characteristics of Aluminum-Silicon Alloy under Lubricated Sliding Conditions

The wear characteristics of aluminum-silicon alloys were studied using a pin-on-disk-type wear tester with different types of lubricants under fully flooded condition. Aluminum-silicon alloy pin specimens were run against the same aluminum-silicon disc surfaces. Wear tests showed that wear resistance of aluminum-silicon alloy was largely influenced by the type of lubricant. Test results showed that hydrocarbon-based fluids such as mineral oils or poly-a-olefins exhibit better wear-protecting property and higher load-carrying capacity than polar base fluids such as polyol esters or polyalkylene glycols. This is contrary to the results of iron-iron systems. The effect of water on the wear and scuffing resistance of aluminum-silicon alloy was also investigated. Water was found to promote the formation of aluminum oxide and silicon oxide layers on the surface which reduced the wear rate and increased scuffing load for aluminum-silicon alloy. Presented at the 50th Annual Meeting in Chicago, Illinois May 14–19,...

A New Tightening Technique for Threaded Fasteners

A new technique for tightening threaded fasteners was proposed aiming to assure the quality and the reliability in the tightening operations. The technique is based on the torque difference and the relative rotation angle in tightening and loosening process, and no preliminary experiment is required. Repeated tightening (and loosening) experiments were performed for different types of lubricant to verify the applicability of this technique. Experimental results show that the preload provided to the joint can be estimated with high accuracy and precision by this technique, and the possibility to boost the reliability of tightening control is confirmed.

An approach to the study of plasto‐elastohydrodynamic lubrication in the wire drawing process part 1: Experimental

AbstractThis paper describes an experimental study of hydrodynamic lubrication in wire drawing in which different types of lubricants (straight oils, emulsions and grease) are used. The experiments were conducted on a specially designed laboratory wiredrawing test rig, to assess the frictional force and film thickness, while drawing an aluminium wire at different speeds. Hydro‐dynamic performance, including frictional force and film thickness, were measured and plotted graphically, showing lubricant and drawing speed as the main influences.Results indicate that the frictional force decreased and the oil film thickness increased using straight oils with high viscosity at high drawing speed.

Determination of the Coefficient of Kinetic Friction of Urinary Catheter Materials

The coefficient of kinetic friction plays an important role in the biocompatibility of urinary catheters. A method for determination of the in vivo coefficient of kinetic friction is described that allows the comparison of the catheter-urethral interaction of the various materials used in the production of urinary catheters and the different types of lubricants.

High-Temperature Lubrication

The maximum temperature at which a mechanical system can operate is often determined by the need for lubrication. The paper considers the various heat sources, ambient temperature, mechanical or chemical inputs, and flash temperatures, and discusses their influence on different types of lubrication. The actual temperature limitations are imposed by physical or chemical changes in the lubricant itself, or by changes in a specific lubrication mechanism such as adsorption. The nature of these types of change is described, together with the dominant importance of residence time on the extent of deterioration. Some actual temperature limits for particular lubricants are listed, and the paper suggests some possible design techniques for extending the upper temperature limits for lubrication.

A Model for the Influence of Pressure on the Bulk Modulus and the Influence of Temperature on the Solidification Pressure for Liquid Lubricants

Two pressure chambers, for compression experiments with liquids from zero to 2.2 GPa pressure, are described. The experimentally measured compressions are then compared to theoretical values given by an isothermal model of equation of state recently introduced for solids. The model describes the pressure and bulk modulus as a function of compression for different types of lubricants with a very high accuracy up to the pressure limit of the high pressure chamber used (2.2 GPa). In addition, the influence of temperature on static solidification pressure was found to be a simple function of the thermal expansion of the fluid.