Abstract: An apparatus protected by corrosion resistance coating, said apparatus comprises an enclosure and heat exchanging elements contained therein wherein the heat exchange element and the enclosure are coated with fluoropolymer composites filled with thermally conductive and thermally insulating fillers, respectively. The composites contain: i) at least one fluoropolymer, and in a preferred embodiment the fluoropolymer is perfluoroalkoxy (PFA), and ii) at least one thermally conductive or insulating filler, and in a preferred embodiment the thermally conductive filler is graphite and the thermally insulating filler is carbon black. The thermally conductive filler is added to the coating for heat exchange elements, e.g. tubes, plates, fins, etc., to enhance heat transfer, while the thermally insulating filler is added to the coating for enclosures, e.g. shell, tube sheets, etc., to reduce the heat transfer to the environment.

Abstract: The present invention provides application of perfluoroalkoxy (PFA) onto metallic substrates to form a pinhole-free protective layer by means of electrostatic powder coating, by adding highly thermally conductive fillers such as graphite or ceramic powders/fibers/whiskers/flakes into virgin PFA powder to improve the thermal conductivity, as well as the application of the filled PFA powder onto various metallic substrates, including convoluted or finned tubes, outer or inner surfaces. Using a simple powder coating technique, a pinhole-free protective layer thinner than a PTFE covering film and with much higher thermal conductivity is produced on the metallic tubes and a physical bond is created at the interface between the PFA and the tube. These make the overall heat transfer coefficient much higher than a PTFE covered tube, which must have a thicker PTFE film to avoid pinhole and is lack of physical bond at the interface.

Abstract: The present invention discloses the fabrication of polymer-coated, coated fiber composites, hybrid composites and a method and apparatus for fabricating the same. The invention provides for the maximum spraying and coating of a roving of coated fibers with molten polymer streams without making physical contact with a solid media, thus simultaneously preventing the fiber surface from getting damaged and stripping off the coating. When metal-coated fiber is used the invention improves the electromagnetic shielding properties of any subsequent product made from the inventive composite. The method and apparatus of the present invention uses sets of nozzle-type sprayers having multiple orifices to enable the thermoplastic or thermoset polymer to penetrate more efficiently into the fiber bundle, thereby providing a more uniform coverage of all fibers. The hybrid composites can consist of two or more types of reinforcements and one or more type of matrix polymer.

Abstract: A reinforced composite material, having isotropic thermal expansion properties and a low coefficient of thermal expansion over at least the temperature range of from about 0° C. to at least about 150° C., which composite material comprises in combination a first continuous phase comprising a three dimensional preformed bonded powder material reinforcement, including a bonding agent, and in which the bonded powder material is chosen from the group consisting of zirconium tungstate, hafnium tungstate, zirconium hafnium tungstate, and mixtures of zirconium tungstate and hafnium tungstate, and a second continuous phase matrix material chosen from the group consisting of aluminium, aluminium alloys in which aluminium is the major component, magnesium, magnesium alloys in which magnesium is the major component, titanium, titanium alloys in which titanium is the major component, engineering thermoplastics and engineering thermoplastics containing a conventional solid filler.

Abstract: A hybrid composite reinforced metal matrix in which the metal is aluminum, aluminum alloy, or a magnesium alloy containing a relatively high percentage of aluminum. In addition to the reinforcement, which is typically alumina, the metal matrix also includes a hardening agent which is at least one intermetallic compound of aluminum with at least one second metal chosen from iron, nickel, titanium, zirconium, cobalt and niobium. The intermetallic compound(s) can be added as a powder to the metal matrix during formation of the composite, or can be created in the composite by adding the at least one second metal as a powder to the molten metal matrix during composite preparation. When the intermetallic compound(s) are created in the composite, during the addition step the second metal powder should be protected from oxidation. If the intermetallic compound is created in the composite, the composite when made initially can be readily machined and is self hardening through repeated heating cycles.

Abstract: A process for preparing a preform for use in a metal matrix composite, particularly for a magnesium metal composite, and a metal matrix composite, typically made by squeeze casting, using the preform. In the preform the reinforcing material typically is silicon carbide, boron nitride, carbon or graphite. The binder used in the preform is magnesium fluoride, which avoids the known problems which result from the high reactivity of magnesium metal with other binders, such as silica and alumina, which results in the formation of magnesium oxide in the reinforced composite. The presence of magnesium oxide crystals in the metal matrix adversely affects the properties of the composite.

Abstract: A process for making a low volume fraction preform for a metal matrix composite including the steps of: mixing a reinforcement with a binder and sacrificial fillers to provide a castable slurry; placing the slurry in a mold to provide a green cast preform; drying the green casting to remove any water and/or solvent; firing the green preform at a relatively low temperature to burn off the sacrificial fillers; firing the green preform at an elevated temperature to sinter the binder to bond the reinforcement together. The firing steps include particular combinations of temperature and time to ensure decomposition of the sacrificial filler and sintering without destruction or cracking of the green preform.