Flame-sprayed aluminum

Flame-sprayed aluminum oxide coating on steel... 

Table 46. Recommended preparation of a flame-sprayed aluminum oxide coating on steel...

Figure 104. Flame-sprayed aluminum oxide coating on steel, DIC. The sample was mounted in epoxy resin before sectioning. Arrows indicate cavities, which have a gray tone that differs only slightly from the aluminum oxide.

Figure 105. Flame-sprayed aluminum oxide coating on steel with Ti02 inclusions, BF. The sample was not mounted before sectioning. Improper sectioning with a high-speed machine has caused the coating to detach from the substrate (as indicated by arrows). The TiOa and the steel substrate have a bright appearance.

Figure 106. Flame-sprayed aluminum oxide coating on steel, with contrast enhanced by Pt/02, BF. The sample was impregnated with epoxy resin before sectioning and then mounted in epoxy resin. The gap at the boundary between the ceramic and the metal (see arrows) is filled with resin, which indicates that this defect was already present before sectioning. The impregnated cavities are dark, the aluminum oxide is gray, and the steel substrate is bright.

The coating metal is melted and kept in the molten condition until it strikes the substrate to be coated. Aluminum and zinc are applied in this manner. Flame sprayed aluminum has a lower density than pure aluminum because of voids in... 

The first robust reflectance standard for mid-IR applications was produced by Frank J. J. Clarke at the National Physical Laboratory. The material is a flame-sprayed aluminum of sufficiently large particle size to produce a highly Lambertian surface. The drawbacks of this material are that the reflectance is in the range of 80%R, a bit low for a high-reflectance material, and that aluminum does form a surface oxide that shows absorbances in the spectral range of interest. 

Catalytic methanation processes include (/) fixed or fluidized catalyst-bed reactors where temperature rise is controlled by heat exchange or by direct cooling using product gas recycle (2) through wall-cooled reactor where temperature is controlled by heat removal through the walls of catalyst-filled tubes (J) tube-wall reactors where a nickel—aluminum alloy is flame-sprayed and treated to form a Raney-nickel catalyst bonded to the reactor tube heat-exchange surface and (4) slurry or Hquid-phase (oil) methanation. 

Flame spray metallising is widely used for the protection of metal against corrosion, especially for in situ protection of stmctural members. The principal metal used for spraying of plastics is sine. Aluminum and copper are also used. If the distance from the part is too great, the zinc solidifies before it touches the part and adhesion is extremely poor. If the molten zinc oxidizes, conductivity and adhesion are poor. If the distance is too short, the zinc is too hot and the plastic warps or degrades. These coatings are not as dense as electrically deposited coatings because of numerous pores, oxide inclusions, and discontinuities where particles have incompletely coalesced. 

Zinc, aluminum, nickel alloys, cobalt alloys and tungsten carbide are applied for sprayed coatings, which are slightly porous. Flame-sprayed zinc coatings are used for corrosion protection of steel and provide similar properties for galvanized coatings. 

The top of the reaction chamber is hinged to permit access to the lower electrode (platen) that holds the wafers. This arrangement is illustrated in Figure 20. The platen is anodized, while the upper electrode is bare aluminum. The upper electrode housing is flame spray coated with aluminum oxide to eliminate electrical discharges above the upper electrode. The platen has pockets to accept wafers and maintain them in fixed positions as it rotates. 

J. Marchal et al., Yttrium aluminum garnet nanopowders produced by liquid-feed flame spray pyrolysis (LF-FSP) of metalloorganic precursors. Chem. Mater. 16(5), 822-831 (2004). 

C.R. Bickmore, K. Waldner, D.R. Treadwell and R.M. Laine, Ultrafine Spinel Powders by Flame Spray Pyrolysis of a Magnesium Aluminum Double Alkoxide, J. Am. Ceram. Soc., 79, 1419-1423 (1996). 

PEEK coatings can be prepared on aluminum or stainless steel substrates using a flame spraying technique. However, the coating obtained in this way is simply an accumulation of the powder with a high porosity and bad mechanical properties. 

Aluminum oxide Plasma flame spray used for extreme abrasion resistance used on steel dies but usually limited to small dies because of expansion problems works best on 18-8 stainless... 

Wielage B, Rahm J, Preparation of MMC structures consist of carbon-fiber aluminum prepregs by using the high velocity flame spraying, Metall, 48(12), 961-966, 1994. 

AlSiC, being electrically conductive, may be readily plated with aluminum to provide a surface for further processing. The aluminum coating may be plated with nickel and gold to permit soldering, or may be anodized where an insulating surface is required. An alternative approach is to flame-spray the AlSiC with various silver alloys for solderabUity. 

An aluminum scrap fire developed near a melting furnace. Fire departments responded and sprayed water on the flames. Suddenly the pot furnace exploded. It is presumed that water from the fire hoses entered the furnace which contained about 900 kg of molten aluminum... 

Flammable gas. Very dangerous fire hazard when exposed to heat, flame, or powerful oxidizers. Moderate explosion hazard when exposed to flame and sparks. Explodes on contact with interhalogens (e.g., bromine trifluoride, bromine pentafluoride), magnesium and alloys, potassium and alloys, sodium and alloys, zinc, Potentially explosive reaction with aluminum when heated to 152° in a sealed container. Mixtures with aluminum chloride + ethylene react exothermically and then explode when pressurized to above 30 bar. May ignite on contact with aluminum chloride or powdered aluminum. To fight fire, stop flow of gas and use CO2, dry chemical, or water spray. When heated to decomposition it emits highly toxic fumes of cr. See also CHLORINATED HYDROCARBONS, ALIPHATIC. 

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