Solid lubricant coatings-Bonded Solid Lubrication Coatings, Process, and Applications | SpringerLink

Tungsten disulphide WS 2 and molybdenum disulphide MoS 2 , which belong to the family of transition metal dichalcogenides, are well known for their solid lubricating behavior. Thin films of WS 2 and MoS 2 exhibit extremely low coefficient of friction in dry enviroments, and are typically applied by sputter deposition, pulsed laser ablation, evaporation or chemical vapor deposition, which are essentially either line- of-sight or high temperature processes. In this paper we have investigated the tribological properties of embedded solid lubricant coatings from WS 2 nanoparticles and compared them to monolithic and alloy films of the same constituents. The patterning methods were used to create two component coatings in which WS 2 were embedded in a Ti matrix. Coatings were deposited using sputter deposition, and co-deposition of WS 2 and Ti was used to deposit the alloy coatings.

Sanders, Coatingz. This allowed conclusions to be made about the influence of the coating microstructure and composition on the tribological response. A nanostructural study using advanced transmission electron microscopy of the initial coatings and examination of the counterfaces after the friction test using different analytical tools helped to elucidate what governs the tribological behavior for each type of environment. A cylinder block as Hotorange tgp claim Solid lubricant coatings, in which said face comprises spiral lands on said bore surface. Main Theme:. Fiber and sheet equipment wear surfaces of extended resistance and methods for Solidd manufacture.

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All rights reserved. Metal Coatings Corp. If you are interested in a product that you do not see lubrivant in the specifications or technical data sheets, feel free to ask us if we would be interested in researching and applying a new product. Surface and Coatings Technology. I am an existing Solid lubricant coatings customer. Most long-wearing films are of the bonded type Chick fil a sweet tea calories are still restricted to applications where sliding distances are not too long. The low-friction characteristics of most dry lubricants are attributed to a layered structure on the molecular level with weak bonding between layers. After the solvent evaporates, the coating cures at room temperature to form a solid lubricant. Retrieved Black pastes generally contain MoS 2. Series coatings offer coqtings corrosion resistanceand prevent the build up coatiings dust, dirt, debris and other foreign contaminants Solid lubricant coatings may hinder your application process. The bonding can be improved by prior phosphating of the substrate.

This invention relates to the art of fluid lubricated metal wear interfaces or contacts, and more particularly to the use of anti-friction solid film lubricants for such interfaces modified to withstand high unit scraping or bearing loads at high temperatures while functioning with either full or partial wet lubrication.

  • This coating is an attractive alternative to fluid lubricants for minimizing friction and preventing seizing and galling, especially in high or low temperature environments where fluids may freeze or vaporize.
  • Specific lubricants were chosen per various customer requests to best fit their needs.
  • Coating thicknesses will vary from application to application.

Tungsten disulphide WS 2 and molybdenum disulphide MoS 2 , which belong to the family of transition metal dichalcogenides, are well known for their solid lubricating behavior. Thin films of WS 2 and MoS 2 exhibit extremely low coefficient of friction in dry enviroments, and are typically applied by sputter deposition, pulsed laser ablation, evaporation or chemical vapor deposition, which are essentially either line- of-sight or high temperature processes.

In this paper we have investigated the tribological properties of embedded solid lubricant coatings from WS 2 nanoparticles and compared them to monolithic and alloy films of the same constituents. The patterning methods were used to create two component coatings in which WS 2 were embedded in a Ti matrix. Coatings were deposited using sputter deposition, and co-deposition of WS 2 and Ti was used to deposit the alloy coatings.

A pin-on-disk POD test was used to examine the frictional behavior and mechanical stability of the coatings, and was carried out in both low and high humidity conditions.

The nanoparticles WS 2 can decrease the friction coefficient of lubricant obviously. However the results showed that their friction reductions have not obvious difference by the POD tribometer.

The analyses of surfaces composition coating conducted by XRD and SEM images showed that nanoparticles form a protective film WO 3 allowing an increase the load capacity of friction rubbed pairs. The main advantage of the nanoparticles is ascribed to the release and furnishing of the nanoparticles from the valley onto the rubbing metal surface and their confinement at the interface. Coatings of WS 2 alone were found to perform well under low-humidity conditions, but poorly under high- humidity.

Alloying of WS 2 with Ti was found to provide some improvement under high humidity. The patterned film, which consisted of columns of WS 2 embedded in a Ti film was found to exhibit friction and wear properties superior to either Ti or WS 2 alone. The coating investigated here have potential applications for cutting tools and metal forming dies that will enhance tool life and reduce the energy expended due to friction forces; as well is used in various tribological fields such as seals, bearings or electrical motor brushes and, also for applications needing excellent lubrication and wear-reducing properties.

Skip to main content Skip to main navigation menu Skip to site footer. Abstract Tungsten disulphide WS 2 and molybdenum disulphide MoS 2 , which belong to the family of transition metal dichalcogenides, are well known for their solid lubricating behavior. Vol 27 No 4 How to Cite. Ilie, F. Tribological properties of solid lubricant nanocomposite coatings on base of tungsten disulphide nanoparticles.

Tribologia - Finnish Journal of Tribology , 27 4 , Make a Submission. Current Issue. Please read our new privacy policy. I accept.

Google Search. Dry lubricants or solid lubricants are materials that, despite being in the solid phase, are able to reduce friction between two surfaces sliding against each other without the need for a liquid oil medium. Critical Processing Factors Base Metal Surface Requirements To maximize coating performance , surface contamination and imperfections must be removed prior to coating application to ensure adhesion and performance results. Furthermore, boron nitride has a high thermal conductivity. Hexagonal boron nitride is a ceramic powder lubricant.

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Series coatings offer strong corrosion resistance , and prevent the build up of dust, dirt, debris and other foreign contaminants that may hinder your application process. Additionally, Series coatings are often used as a barrier to prevent galvanic corrosion at the point of contact of two dissimilar metals. To maximize coating performance , surface contamination and imperfections must be removed prior to coating application to ensure adhesion and performance results.

Please note that certain Series coatings are migratory in nature and may transfer coating materials onto interfacing surfaces. Masking of select surfaces where coating voids are required is available. In the event masking is required, highlighted or marked prints identifying critical surfaces are extremely helpful in ensuring your parts are processed to spec.

Please complete our Coating Requirement Questionnaire or call us at 1. Coating Requirements Questionnaire. Coating Thickness Coating thicknesses will vary from application to application. Dry Lubrication Series coatings afford excellent self-lubricating surface properties and often serve as more robust product alternatives to traditional lubricants and anti-seizing agents such as oils. TFC provides solid film lubricant coatings to aerospace, industrial, and the following military specifications:.

Download Our Brochure. Toggle navigation. Process TFC maintains both automated and manual facilities for the application of solid film lubricants, with various sized spray booths, fixturing and curing ovens to accommodate a variety of shapes and sizes. Typical Applications Equipment with heavy loads prone to seizing Moving parts such as gears, ball joints, bearings, rollers, fasteners, and slides Dusty or dirty environments that would otherwise contaminate wet lubricants Harsh environments where contamination or degradation may occur by contact with chemicals, solvents or fuels High temperature applications Protection from galvanic corrosion in dissimilar metals Inaccessible parts where maintenance of lubrication is difficult or impossible due to location Substrates Virtually all metals TFC Anodized Titanium Products TFC Hard Anodized Aluminum Products Download Our Brochure.

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USA - Thermoset polymer/solid lubricant coating system - Google Patents

This invention relates to the art of fluid lubricated metal wear interfaces or contacts, and more particularly to the use of anti-friction solid film lubricants for such interfaces modified to withstand high unit scraping or bearing loads at high temperatures while functioning with either full or partial wet lubrication.

The utility of certain solid film lubricants for bearings has been known for some time. The coating offers limited friction reducing characteristics. Unfortunately i the graphite is not exposed except by significant wear of the metal, thus never realizing significantly lower friction; ii the metal is in a molten condition prior to trapping or burying the graphite causing thermal effects and distortions; and iii oxides of the metal serve as the primary lubricant.

The prior art has also appreciated the advantage of thermally spraying by oxy-fuel aluminum bronze as a solid film lubricant onto cylinder bore surfaces of an engine as demonstrated in U. The lubricating quality of such coating at high temperatures is not satisfactory because i it lacks compatibility with piston ring materials which usually comprise cast iron, molybdenum coated cast iron, or electroplated hard chromium; and iii thermal spraying of the material by oxy-fuel is not desirable because of very high heat input necessitating elaborate tooling to rapidly dissipate heat to avoid distortion of its coated part.

One of the coauthors of this invention has previously disclosed certain solid lubricants operable at high temperatures, but designed for either interfacing with ceramics, not metals, at low load applications in the absence of any liquids, or with metals in an oilless environment.

One solid lubricant disclosed comprised graphite and boron nitride in a highly viscous thermoplastic polymer binder spread in a generous volume onto a seal support comprised of nickel and chromium alloy. The formulation was designed to provide a hard coating which softens at the surface under load while at or above the operating temperature and functioning only under dry operating conditions.

Thermoplastic polymer based formulations, without modification, are unsatisfactory in meeting the needs of a highly loaded engine component, such as a cylinder bore, because the interfacing surfaces are subject to wet lubrication, the unit loads are significantly higher approaching psi , and the surface temperatures are higher, causing scraping.

Another solid lubricant disclosed was halide salts or MoS 2 but not as a combination in a nickel, copper, or cobalt binder; the coating, without modifications, would not be effective in providing a stable and durable anti-friction coating for the walls of an internal combustion cylinder bore, because the formulations were designed to operate under dry conditions and against ceramics primarily lithium aluminum silicate and magnesium aluminum silicate, and, thus, the right matrix was not used nor was the right combination of solid lubricants used.

Particularly significant is the fact that the formulations were designed to produce a ceramic compatible oxide e. These systems were designed to permit as much as microns wear. In the cylinder bore application, only micron wear is permitted. Another object of this invention is to provide a lower cost method of making anti-friction coated cylinder walls of light metal by rapidly applying select materials at room temperature in reduced or selected areas of the bore wall while achieving excellent adherence and precise deposition, the method demanding less rough and finish machining of the bore surface.

The invention, in a first aspect, is a solid film lubricant system useful in protecting a metal wear interface subject to high temperatures. The means for supporting the mixture may comprise a lands in the interface that extend above the polymer, or b a transition zone material or substrate between the polymer and interface that provides an elastic modulus exceeding 5 million psi, the material or substrate being comprised of ingredients selected from the group of: i nickel, copper, cobalt, iron, or manganese; ii intermetallic compounds derived from nickel, chromium, aluminum, vanadium, iron, tungsten, manganese, and molybdenum; and iii cast iron or steel.

The system's solid lubricants preferably should have a submicron average particle size. The thermoset polymer is preferably comprised of a thermoset epoxy resin, solvent or water-based carrier, a catalyst curing agent that cross-links the epoxy, and a dispersing or emulsifying agent. Another aspect of this invention is a method of making anti-friction coated surfaces subject to sliding loads.

The method comprises: a providing a light metal based cylinder surface i. The solid lubricant mixture comprises at least two elements selected from the group consisting of graphite, MoS 2 , and BN, and the polymer adheres the mixture to the layer upon flowing thereagainst.

The distribution step may be carried out by different species or modes, including: i spraying, roller transferring, or silk screening an acetate, ketone, or mineral spirit emulsion containing the mixture and polymer followed by curing to provide a stable coating; ii spraying or roller-transferring, or brush painting or imprinting a water-based emulsion containing the mixture and the polymer, the emulsion being cured to provide a stable coating; or iii adhering a tape carrying the mixture and polymer which is subsequently cured.

The distribution for the above method should be controlled to coat thinly, usually in the thickness range of microns however, the thickness can be up to microns ; the coating is honed, after curing, to a coating thickness of 0.

However, higher thicknesses up to 0. The load supporting face for the surface of the block may be either a series of spiral grooves machined in the cylinder bore wall to create an undulating face; or a substrate coating of nickel, copper, cobalt, iron, zinc, and tin; or of intermetallic compounds; or of cast iron or steel. The coated block works well with a piston assembly having advanced or conventional piston rings; the gap between the piston body and the coating is significantly less i.

To achieve a significant reduction in the coefficient of friction at high temperatures between normally oil-bathed metal contact surfaces, loaded to at least 10 psi, the coating system cannot rely on graphite or any one lubricant by itself, but rather upon a specific combination of solid lubricants in a special polymer that assists in replenishing graphite with water at high temperatures.

As shown in FIG. Such means B may be an intermediate layer or coating, as shown in FIG. The ingredients for such intermediate layer should provide an elastic modulus exceeding 5 million psi.

The ingredients are selected from the group consisting of i nickel, copper, iron, zinc, tin, manganese, or cobalt; ii intermetallic compounds derived from nickel, manganese, chromium, aluminum, vanadium, tungsten, molybdenum, iron, carbon; and iii cast iron or steel.

The interface is comprised of a light metal such as aluminum, titanium, or magnesium. Alternatively, means B may be provided by grooving 10 of the interface C preferably spiral grooving for interior cylinder surfaces as shown in FIG.

The lands 11 of the parent interface metal, created by the grooving, provide the support for loading of at least 10 psi; the layer A is coated both onto the lands 11 and within the valleys 12 of the grooves. Upon sliding contact with the opposing surface, the polymer mixture is rubbed away from the lands 11 to provide the mechanical support needed. The interface containing the grooves can be a diffusion-type hard layer or a cast-in-surface treatment to achieve a high elastic modulus layer structure such as aluminum silicate or silicon carbide forming a particle or fiber-reinforced metal matrix composite MMC.

The layer A can then function as low shear solid film lubricant to provide low friction. Friction in an oil-bathed environment will be dependent partly upon fluid friction in the oil film layers in a fluid sheared at different velocities commonly referred to as hydrodynamic friction , and, more importantly, dependent on dry or coulomb friction between contacting solid, rigid bodies also referred to as boundary friction.

Dry friction is tangential and opposed to the direction of sliding interengagement. The weight of a block 13 imposes a normal force N that is spread across several small load forces N-1 at each interengaging hump 14 see FIG. The composite of all the tangential components of the small reaction forces F-1 at each of the interengaged humps 14 is the total friction force F.

The humps are the inherent irregularities or asperities in any surface on a microscopic scale. When the interengaging surfaces are in relative motion, the contacts are more nearly along the tops of the humps and therefore the tangential reaction forces will be smaller.

When the bodies are at rest, the coefficient of friction will be greater. Friction is influenced by the attraction of the two surfaces, the deformation and tearing of surface irregularities, hardness of the interengaged surfaces, and the presence of surface films such as oxides or oils. As a result, actual friction will be different from idealized perfect contact friction, and will depend upon the ratio between shear and yield stresses of the interengaged surfaces.

Thus, the presence of a film 16 on each of the interengaging surfaces 17, 18 see FIG. Where the film is supported by a hump, the shear in the film will be greatest; thus, the asperities or humps facilitate lowering of friction in comparison to a perfectly flat surface with a film thereon. Friction is also influenced significantly by temperature because high local temperatures can influence adhesion at the contact points.

This is accounted for in the friction equation:. The coefficient for block graphite rapidly increases to above 0. Contrast this with the coefficient of friction performance and wear performance of the coating system of this invention represented in FIG. You will note that the coefficient of friction generally uniformly stays below 0. The coating for FIG. The oil-attracting solid lubricant mixture should comprise two elements selected from the group consisting of graphite, molybdenum disulfide, and boron nitride.

Molybdenum disulfide reduces friction in the absence of oil or in the presence of oil, and, most importantly, supports loads of at least 10 psi at such high temperatures. Molybdenum disulfide is also an oil attractor and is very useful in this invention. Boron nitride is an effective oil attractor. Particle size of the individual ingredients may be as follows: graphite is introduced into the mixture in the range of 0.

The mixture is typically ball-milled to produce an average particle size of 0. The combination of all three elements will provide a coefficient of friction which is in the range of 0.

The latter is particularly beneficial as an impregnant onto a porous substrate such as plasma sprayed hard metals. The system of this invention can be used not only for cylinder bore coatings, but also for engine camshafts, compressor elements, oil pumps, air conditioning equipment, transmission gears, and starter clutches, all of which experience some degree of wet lubrication.

The system is most beneficial to a wet lubricated cylinder bore since it experiences reversion between oil-bathed and oil-starved conditions regularly. The oil-starved condition is experienced at engine start-up where about 35 strokes of the piston is without oil until engine reaches rpm and operating temperature.

Temperature stability is important because typical engine cylinder bore wall will, at certain zones thereof and under certain engine operating conditions such as failure of coolant or oil pump, etc.

If the means for supporting the mixture under loads of at least 10 psi at high temperatures is an underlayer or intermediate layer, such layer should have ingredients that are selected to be resistant to compressive shear and resist plastic deformation, and possess a high elastic modulus and shear stress.

Ingredients effective for such intermediate layer comprise alloys of iron, aluminum, nickel, vanadium, tungsten, manganese, molybdenum, and chromium, which contain extremely hard intermetallic particles such as lave phases such as in Tribaloy. The ingredients of such underlayer should have an elastic modulus exceeding 5 million psi. Nickel alloys have an elastic modulus of 27 million psi, silicon carbide of 60 million psi, tool steel of 29 million psi, cast iron of 17 million psi, nickel oxide of 24 million psi, and Tribaloy of 30 million psi.

The carrier for such polymer may be mineral spirits or butyl acetate. Both Tribaloy, stainless steels such as iron-manganese-chromium or iron-nickel-chromium alloys, nickel-chromium and aluminum alloys, and the thermoset polymer have a very important characteristic in that they are not affected by formic acid which is formed when an engine is fueled with flex fuel, such as containing methanol. An extremely important and new feature of the inventive solid lubricant system herein is a lower coefficient of friction at higher temperatures and while in the environment of an oil-bathed interfacing contact, and provides lubrication and protection against scuffing even when oil fails and oil film is lost.

Under these severe conditions, conventional surfaces rubbed by cast iron or steel piston rings show rapidly increasing friction and experience scuffing failures in only a few seconds. However, with the solid film lubricant herein, coating scuffing does not occur even after long periods of exposure to severe thermal environments. In addition, this coating has excellent noise attenuation characteristics which reduce the piston noise significantly while providing improved gas blow-by during engine operation, particularly in case of aluminum engine blocks.

It is preferred to coat the parent bore surface 17 of a cylinder block 18 directly to reduce the steps needed to prepare the block If a liner insert is used, it is adapted for a shrink-fit within the receiving cavity or bore 17 of the cylinder block as shown in FIG. The liner insert may be coated independently of the block for ease of manipulation and ease of access to the interior of the liner.

The liner would be constituted of the same or similar material as that of the parent bore 17; a light metal alloy, selected from the group of aluminum, magnesium, and titanium, is used for the bore surface.

However, the liner can be any metal that has a higher strength as the metal of the parent bore wall; this is often achieved by making an alloy of the metal used for the parent bore wall. For example, C or C aluminum alloys for the liner are stronger than the aluminum alloy commonly used for aluminum engine blocks.

The liner must have, generally, thermal conductivity and thermal expansion characteristics essentially the same as the block. The manner of assembling the liner to the block is described later, such as by use of a thermal bonding layer 19 of flake copper in an epoxy matrix.

The liner may also be cast-in-place while casting the bore wall. Exposing fresh metal of the bore surface 15 may comprise wire brushing using a hardened stainless steel wire diameter of about 0. This step can be avoided by rough-machining the bore surface to micro-inch or coarser surface roughness, if desired and then degreasing and applying the coating.

The surface is prepared by degreasing with OSHA approved solvent, such as ethylene dichloride, followed by rinsing with isopropyl alcohol. The surface is grit blasted with clean grit. Alternately, the surface can be cleaned by etching with dilute HF acid followed by dilute HNO 3 and then washed and rinsed. Wire brushing also helps to move the metal around without burnishing. The bristles of the wire brush should have a hardness of at least Rc 45, preferably about Rc It is sometimes desirable to additionally etch the brushed surface with HNO 3 or HF acid diluted in water or alcohol.

The wire brushing and etching exposes elemental metal that facilitates adherence of the coating A thereto. It is, in most cases, necessary to prepare a coatable surface 15 that is a segment 20 of the entire bore surface 17 or liner insert Such segment 20 would be the area for depositing the underlayer or coating 13 which is a load supporting modification.

The distance 20 represents the hottest zone of the bore wall where variably lubricated contact and high contact pressure is most susceptible to drag and piston slap and which is the source of a significant portion of engine friction losses. Such contact in such zone causes scuffing of the bore wall in case of partial or full failure of liquid lubricant.