Showing papers on "Coating published in 1986"

The microstructure of sputter-deposited coatings

Abstract: Microstructure is a critical consideration when polycrystalline or amorphous thin films are used for applications such as microcircuit metallization layers and diffusion barriers. The trend in device fabrication toward lower processing temperatures means that such coatings must often be deposited at substrate temperatures T that are low relative to the coating material melting point Tm. The structure of vapor deposited coatings grown under these conditions consists typically of a columnar growth structure, defined by voided open boundaries, which is superimposed on a microstructure which may be polycrystalline (defined by metallurgical grain boundaries) or amorphous. The voided growth structure is clearly undesirable for most applications. Its occurrence is a fundamental consequence of atomic shadowing acting in concert with the low adatom mobilities that characterize low T/Tm deposition, and its formation can be enhanced by the surface irregularities which are common to microcircuit fabrication. This pap...

Material selection for hard coatings

Abstract: Multicomponent refractory material systems can provide opportunities for specific materials for wear resistant coatings. The multitude of potential hard coating materials can be subdivided into three groups according to variations in chemical bonding character of the compounds. Many fundamental relations between the position of coating material components in the Periodic Table of the elements and the properties can be used to optimize these material selections. However, restrictions exist because of increasing hardness and strength which primarily decrease toughness and adherence. Multicomponent boride, carbide, nitride, and oxide systems are discussed in view of their potential as coating materials. Additional options for materials selection and optimization arise from the possibility of adjusting specific microstructures in the layers, especially in multilayer and multiphase coatings.

Underground utility equipment vault

Abstract: An improved underground utility equipment vault is comprised of at least two concentrically disposed chambers. The inner chamber is a non-electrically conductive material such as wood and is disposed in spaced concentric relationship within the outer chamber which is metallic, preferably steel. The exterior surface of the outer chamber is provided with a protective dielectric coating and cathodic protection in the form of sacrificial anodes. The inner chamber is provided with heat vents adjacent its uppermost surface area and cold air returns adjacent its lowermost surface area. The heat vents may be provided with exhaust fans. The inner chamber is provided with above ground air communication and an entryway. The interior of the inner chamber and electric gear therein contained is electrically isolated from the outer chamber and the vault exterior.

A review of the present state of art in hard coatings grown from the vapor phase

Abstract: Hard‐coating materials range from ultrahard materials such as ‘‘diamondlike carbon’’ through refractory compounds to alloys. However, transition‐metal carbides and nitrides have achieved by far the highest level of commercial success. Titanium nitride and titanium carbide are the most studied and used. In this paper a review of the hard coating literature is given and includes in addition to nitrides and carbides also oxides, borides, mixed compounds, metals and alloys, and ‘‘diamondlike’’ carbon coatings. Only coatings grown from the vapor phase are discussed. Some considerations involved in selecting coating/substrate combinations as well as basic concepts of hardness and hardness measurements are also given. For example, it is shown that in order to measure the hardness of the coatings correctly the ratio between the film thickness and the depth of the indentation has to exceed a critical value, which depends on the coating/substrate combination. For TiN on steel, the coating thickness has to be a fact...

On structure and properties of sputtered Ti and Al based hard compound films

Abstract: After investigating basic correlations between process and film characteristics in previous works new multicomponent hard coatings, on the basis of Ti–Al and Ti–Zr, have been deposited by magnetron sputtering. These ternary and quaternary nitrides are crystallizing in a face centered cubic TiN lattice with reduced or enlarged lattice parameters depending on the amount and the radius of foreign atoms. Improved wear behavior compared to chemical vapor deposition (CVD) TiN coatings has been stated with (Ti,Al)N, (Ti,Zr)N, and (Ti,Al,V)N coatings. According to these results the development of the coating material itself will be of major interest in the future.

A review of adhesion test methods for thin hard coatings

Abstract: Adhesion to the substrate is the most important property of a coating. Previously unattainable adhesion levels can be achieved by modern physical vapor deposition and chemical vapor deposition techniques. There is an urgent need to develop standard techniques of adhesion evaluation, to ensure user confidence and promote the widespread use of coating methods. An adhesion test for hard tribological coatings should be easy and quick to carry out and the results should be easy to interpret. The test should be practicable for real tools and machine parts. Special sample preparation should not be required. There are at least nine different basic techniques for adhesion assessment: pressure sensitive tape test, acceleration (body force) testing, electromagnetic stressing, shock wave testing, tensile and shear testing, laser techniques, acoustic imaging, indentation tests, and scratch testing. These methods are discussed in this paper in the light of the requirements mentioned above. In the author’s view only las...

Introducer sheath assembly

Abstract: An introducer sheath includes a connector body having an inlet and an outlet; a flexible tube for intravenous use at the outlet, including a helical coiled spring having a plurality of coils, each coil spaced from an adjacent coil, and a thin cylindrical wall prepared from a protective coating composition completely surrounding the spring to define an inner and an outer wall surface, the portion of the cylindrical wall surrounding each coil having a first thickness and the portion of the cylindrical wall between the spaced coils having a second, smaller thickness, with the inner and outer wall surfaces being indented thereat, the coating composition comprising a thermoplastic polymeric material dissolved in a solvent solution, the composition having a solids content ranging from about 4% to about 18%, and said solution comprising a solvent selected from the group consisting of tetrahydrofuran, dioxane, methyl ethyl ketone, dimethylformamide, cyclohexane, and mixtures thereof, formed on a helical coiled spring by dipping the latter therein and then drying at room temperature; and a valve assembly including a first elastic membrane having a central aperture, and a second elastic membrane in sealing contact with the first elastic membrane and having a slit extending therethrough at an angle to the direction of fluid flow in the introducer sheath, the slit being in fluid communication with the central aperture.

A comparative study of porous coatings in a weight-bearing total hip-arthroplasty model.

Abstract: The purposes of this study were to compare ingrowth of bone into three types of porous coating and to determine the effect of the type of porous coating and the degree of coverage of the stem on the remodeling of bone on the femoral side in cementless hip arthroplasty. A left total hip arthroplasty was performed in forty dogs. Thirty of the dogs had a titanium-alloy femoral prosthesis that had had one of three types of commercially pure titanium porous material applied along the length of the anterior and posterior surfaces of the stem: ten with sintered fiber-metal, ten with sintered beads, and ten with plasma flame-spray coating. The remaining ten dogs had a femoral component that was circumferentially coated with commercially pure titanium that was plasma flame-sprayed along the length of the stem. In each group, five animals were killed at one month and five were killed at six months. Ingrowth of bone into all three types of porous coating was observed, indicating secure fixation of all components. By six months, there was more ingrowth of bone and new medullary bone adjacent to the proximal and distal aspects of the stems compared with the middle level of the stems in all groups. No significant difference in ingrowth of bone was observed in the beaded surface (25.2 per cent) and the fiber-metal surface (16.6 per cent) at one month, but at six months there was significantly less ingrowth into the beaded surface (23.3 per cent) than into the fiber-metal surface (37.3 per cent). In all groups, a proximal-to-distal gradient of loss of cortical bone was observed by six months. The group of dogs that had the stem with the circumferential coating experienced more severe loss of bone than did the three groups that had a stem with a partial coating. The magnitude of loss of bone was dependent on the extent rather than the type of porous coating.

High laser damage threshold porous silica antireflective coating

Abstract: A quarterwave-thick narrow-bandwidth antireflective coating for fused silica optical components and KDP crystals has been developed. The coating consists of porous silica prepared from a silica sol in ethanol. It is applied by dip or spin from a solution at room temperature and requires no further treatment. The laser damage threshold levels are about equal to the surface damage thresholds of the uncoated substrates.

Correlation of surface acoustic wave device coating responses with solubility properties and chemical structure using pattern recognition

Abstract: : Twelve surface acoustic wave (SAW) device coatings were exposed to eleven chemical vapors and responses were correlated with solubility properties and coating structure to determine possible vapor/coating interaction mechanisms. Hydrogen bonding ability is implicated as a significant vapor/coating interaction mechanism. Pattern recognition schemes applied to the preliminary data aided in solubility property/response correlations. Principal component analysis demonstrated good separation of different classes of chemical vapors tested. Hierarchical clustering provided additional evidence of the correlations between solubility properties and the observed clustering. In addition, pattern recognition methods were used to determine potential selectivity of an array detector using these coatings. Learning techniques show that one fourth of the sensors can adequately separate compounds of interest from chemically similar interferences.

Self-assembled nanometer lithographic masks and templates and method for parallel fabrication of nanometer scale multi-device structures

Abstract: Articles exhibiting fabricated structures with nanometer size scale features (nanostructures), typically a device comprising nanostructures of a functional material on or in a substrate of dissimilar material, are produced by a method employing a substrate base or coating and a thin layer serving as a lithographic mask or template, consisting of a self-assembled ordered material array, typically a periodic array of molecules such as undenatured proteins, exhibiting holes, thickness or density variations. It is possible to produce complex structures containing large numbers of nanometers scale elements through a small number of simple steps.

Precured coated particulate material

Abstract: The present invention relates to coated particulate matter wherein the particles are individually coated with a cured combination of phenolic/furan resin or furan resin to form a precured resin coating on a proppant such as sand, thereby substantially improving the chemical resistance of the proppant over one having a straight phenolic precured coating. Another embodiment of this invention involves the use of multiple resin coatings on the particulate matter to form a final layered coating containing the desired amount of cured resin. This multiple coating of particulate material results in a final coated product that has a smoother and more uniform surface than particulate material having its entire resin coating applied in a single operation.

Optical assay: method and apparatus

Abstract: Optical assay apparatus (Figure 2) of the type comprising an optic waveguide (1; 1'; 1") and a coating (7; 7') sensitized to a specific assay species Light signal response is enhanced by coupling a resonant metallic medium (17; 17'; 17") to the waveguide (1'; 1") and to the sensitized coating (7; 7') To this end a metal coated transparent buffer layer (17) may be interposed between the waveguide (1') and the sensitized coating (7) Alternatively (Figure 3), a metallised optically matched grating (17') can be used in place of the buffer layer (17); or, the metallic medium (Figure 4) can be of particulate form, each particle (17") having a sensitized coating 7'

Thermal conductivity of coated filler composites

Abstract: The temperature field and thermal conductivity of a coated‐fiber composite were studied analytically. The analytical model is based on the classical separation of variables and equivalent‐inclusion method. Closed‐form solutions are given for the thermal conductivity of a coated‐fiber composite. The present results on the temperature gradient in a thin coating were compared with those based on the thin‐coating model by Walpole, resulting in a complete agreement when the thickness of the coating approaches zero. Then, a parametric study was conducted to study the effect of coating properties and other parameters on the thermal conductivity of the composite. It was found in this parametric study that the use of highly conductive (or resistive) coating, even if its thickness is small, is quite effective in enhancing the overall thermal conductivity (or resistivity) of the composite.

Method for plasma - coating a semiconductor body

Abstract: A method for the plasma coating of a layer of material atop a semiconductor body, said method and apparatus adapted to substantially prevent damage to the semiconductor body by energetic vaporized species developed during the coating process. The invention has particular utility in the high volume fabrication of thin film semiconductor devices and may be readily adapted to provide the transparent conductive electrode of photoresponsive devices in a continuous roll-to-roll deposition process.

The factors affecting the thickness of sol-gel derived silica coatings prepared by dipping

Abstract: A partially hydrolysed solution of tetraethoxysilane was used to prepare thin glassy films on glass microscope slides by dipping. The thickness of these films after heat treatment to 500 °C was determined as a function of the withdrawal speed and the properties of the coating solution, such as viscosity, density and surface tension. The results were fitted to available theories of dip coating and acceptable agreement was obtained for coating solution viscosities below around 8 mPas and withdrawal speeds in the range 5 to 15 cm/min. In addition, the thickness of selected coatings were obtained at a range of heat treatment temperatures. Differences in the thickness of coatings prepared after different maturing times of the solution are also discussed.

Immersion pyrometer with protective structure for sidewall use

Abstract: Temperature sensing apparatus for use in the sidewall or bottom of a vessel for containing molten metal. A temperature sensing element is mounted within a sheath which is provided with a sacrificial coating to protect the sheath from premature oxidation such as may occur during a gas-flame pre-heat cycle. The sheath which is being protected against premature oxidation by the sacrificial coating is a composite of a closed end metal tube and a plurality of porous cermet layers of aluminum oxide-chromium oxide-molybdenum with the concentration of molybdenum decreasing in proceeding from the inner cermet layer to the outer cermet layer. The outer cermet layer of the sheath is covered by a ceramic layer of aluminum oxide. The sacrificial coating consists of a layer of zirconium oxide in combination with and covered by a layer of fibrous alumina. The sacrificial coating is typically destroyed by the end of a pre-heat cycle.

Protective coatings – purpose, role, and design

Abstract: A wide range of coatings and coating processes is now available for protecting components in gas turbines operating in a variety of conditions. Coated aerofoils are less likely to fragment, and they keep their original shape – and hence their aerodynamic efficiency – for longer. Aluminide diffusion coatings perform well in relatively clean environments, especially on alloy bases which have a moderate resistance to the many forms of hot corrosion, and with additions of chromium or platinum they provide resistance to sulphate–induced hot corrosion. In hotter or more aggressive corrosive environments, overlay coatings based on MCrAlY (M = Fe,Co, Ni), CoCr, and MCrSi(Al), applied by electron beam evaporation or plasma spraying, are suitable for a wide variety of applications. It is not yet possible to design coatings from first principles for particular applications. Development still proceeds by repeated selection and testing, but modern technology has made this approach more effective than it was in...

Electrospray coating process

Abstract: An electrostatic coating system for applying very thin coating to a substrate in air at atmospheric pressure comprises a plurality of spaced capillary needles positioned in at least two rows and fed with coating liquid via a manifold. The needles are disposed concentric within holes in an extractor plate, a potential is developed between the capillary needles and the extractor plate affording a reduction of the liquid to a mist of highly charged droplets drawn to the substrate by a second electrical field. Insulative layers on the extractor plate provide increased droplet control.

Treated glass fibers and aqueous dispersion and nonwoven mat of the glass fibers

Abstract: Treated glass fibers having adequate protection for gathering into strands and when chopped being more dispersible in aqueous media. The treated glass fibers have a coating of an aqueous treating composition, wherein the solids have a cationic surfactant having one or more primary, secondary and/or tertiary amine moieties and one or more water dispersible, poly(oxyethylene-oxyalkylene) copolymer having an oxide ratio of about 78 to about 22 to about 99 to about 1 and an average molecular weight of at least 15,000, and one or more polar functional coupling agents. Optionally, the solids may also have one or more starches that are insoluble or only incompletely soluble in cold water. Glass fibers treated with the aqueous treating compositions and produced into wet or dry chopped glass fiber strands having lengths of about 1/16 of an inch (1.58 mm) to about 3 inches (76.2 mm), have good dispersibility in aqueous media with or without addition of dispersing agents. Nonwoven, sheet-like mat is produced from aqueous dispersions having the chopped treated glass fibers, where some of the water is removed and polymeric binders, commonly referred to as wet strength binders, are applied and the mat is cured. The resulting nonwoven, sheet-like mat product has very good strength properties for use as a reinforcing element for roofing products, construction products and flooring products.

Microsuspension process for preparing solvent core sequential polymer dispersion

Abstract: The present invention relates to a sequential polymerization process for preparing a water-insoluble dispersion of core/shell particles. In one embodiment the process may be employed to produce a particulate dispersion useful in making water-based coating compositions wherein on drying the particulate dispersion serves as an opacifying agent. In another embodiment the process may be employed to microencapsulate a hydrophobic target material, such as a biocide or herbicide.

Fiber for lateral beaming of laser beam

Abstract: A fiber for lateral beaming of a laser beam, wherein an affected portion in a cavity of an internal organ in a living body is irradiated by the laser beam in a through-endoscopic manner. The fiber for lateral beaming of the laser beam is constructed such that a transparent tubular member is coupled to the forward end portion of a fiber through two coating layers, and an anti-reflection coating layer is formed on a laser beam exiting surface of the transparent tubular member. Owing to the anti-reflection coating layer, this fiber for lateral beaming is free from the harmful leaking beam. Since the transparent tubular member is connected to the fiber through the two coating layes, the fiber can avoid being broken.

Composite article and method of making same

Abstract: A method of making a composite article and a composite article specifically adapted for use in high temperature, corrosive and errosive environments comprising a carbon fibrous substrate, including a pyrolytic carbon sheath formed about each fiber of the substrate; a metallic carbide, oxide, or nitride compliant coating over the coated fibers of the substrate; and an impermeable metallic carbide, oxide or nitride outer protective layer formed about the entire periphery of the coated substrate. In accordance with the method of the invention, the compliant metallic coating is applied to the fibers in a manner such that any mechanical stresses built-up in the substrate due to a mismatch between the coefficient of thermal expansion of the fibrous substrate and the coating are effectively accomodated.

Gas generating material

Abstract: A gas generating grain has a water-based particulate booster coating thereon. The coating comprises an alkali metal azide, a water-soluble inorganic oxidizer in approximately a stoichiometric proportion of oxidizer to azide, and a nucleating amount of a small particle size metal oxide, preferably selected from the group consisting of iron oxide, nickel oxide and aluminum oxide. The coating is applied to said grain from a water slurry and dried, and when dried has an average particle size of less than about 50 microns.

Biaxially oriented polyester film

Abstract: PURPOSE:To obtain the titled product having improved slipperiness and antistaticity and excellent windability in film-forming process, and useful as a base of a high-density magnetic recording material, by coating the surface of a film with a coating agent containing a specific vinyl resin and drawing the coated film. CONSTITUTION:At least one surface of a polyester film is coated with a coating agent composed of a vinyl resin containing styrene-sulfonic acid (salt) as a constituent component to a thickness of preferably 0.01-1mum, and the coated film is drawn to obtain the objective product. The coating agent is preferably added with a water-soluble acrylic resin, a water-soluble polyester containing sulfonic acid salt, and silica sol to obtain a film having high transparency, slipperiness and adhesivity, especially excellent adhesivity to the magnetic layer of a magnetic recording medium.

Method of preparation of variable permeability fill material for use in subterranean formations

Abstract: A method and composition for filling voids in a subterranean formation to provide a fill having a substantially uniform permeability. A viscosified aqueous fluid is prepared to which is added a first particulate having a particle size no greater than about 10 mesh, another particulate having a particle size of less than about 1/7th the median diameter of the first particulate and a resin composition capable of coating at least a portion of the particulate. The fluid is introduced into a subterranean formation to fill at least a portion of the voids that may be present in the formation, compacted and allowed to set to provide the permeable fill material.

Thixotropic coating composition, process for coating a substrate with such coating composition and the coated substrate thus obtained

Abstract: The invention provides for a thixotropic coating composition comprising (1) a binder and (2) a sag control agent which is the reaction product of (a) a symmetrical aliphatic or homocyclic diisocyanate and (b) a monoamine or diamine having at least one primary amino group and ether group, the coating composition containing 0.1 to 30 percent by weight of the sag control agent. The invention also relates to a process for coating a substrate using said coating composition and to the coated substrate thus obtained.

Broadband antireflective coating composition and method

Abstract: The invention relates to antireflective coatings and to a process for depositing the antireflective coatings on solar collector cover plates, optical elements such as lenses and windows in high-energy visible and near-IR lenses and on other glass or metal or metal-alloy or single crystal surfaces, including the steps of hydrolyzing an alkoxysilane, titanium alkoxide, aluminum alkoxide, tantalum alkoxide, niobium alkoxide, or other alkoxy compounds, or a mixture thereof, depending upon the final coating composition desired; to prepare polymeric solutions of the alkoxy compound/or compounds in which the polymer molecules or macromolecules (i.e. the primary particles) grow with time; depositing layers of coatings from the polymeric solutions by state of the art processes (such as spraying, dipping or spinning method), and drying to form chemically bound microporous gel layers; thermally treating the gel-coating in a manner adapted to remove solvent, excess water and residual organics from the gel coating. Microporous coatings produced by the above procedure will be characterized by graded particles and hence graded porosity across the coating thickness, --larger porosity on the top surface and smaller porosity in the substructure--, and will have gradual transition of refractive index (i.e. graded refractive index) across the coating thickness. Coatings produced by the process of this invention can be used to reduce or eliminate reflection losses from surfaces of transmitting optical elements over a wide spectrum of light waves.