Wire flame spraying

Wire flame spraying Electric arc flame spraying Powder flame spraying Plasma flame spraying Hypersonic flame spraying... 

The most important groups of materials for wire flame spraying and arc spraying are... 

Thermal or Flame Spray Process. The earliest experiments in metal spray used molten metal fed to a spray apparatus, where it was dispersed by a high speed air jet into tiny droplets and simultaneously blown onto the surface of the part to be covered. The metal solidified on contact. Modem processes use a more convenient source than premelted metal. Spray heads using a flame or an electrical arc to melt metal wires or powders directly are much more convenient. These are the only types used on a large scale in the United States. 

Rhodium-platinum alloys containing up to 40% Rh are used in the form of wire or ribbon in electrical resistance windings for furnaces to operate continuously at temperatures up to 1 750°C. Such windings are usually completely embedded in a layer of high-grade alumina cement or flame-sprayed alumina to prevent volatilisation losses from the metal due to the free circulation of air over its surface. Furnaces of this type are widely employed for steel analysis, ash fusions and other high-temperature analytical procedures. 

In recent years, there has been interest in using zinc as a power-impressed anode for the cathodic protection of steel in concrete. The zinc is flame sprayed onto a grit blasted concrete surface to a final film thickness of approximately 250 m. A primary anode is necessary. Early systems used brass plates as the primary anode, but more recent systems used platinised titanium or niobium wire anodes as the primary current conductor. 

Figure 10.25 Thermal spray gims for a) arc spra3ring, b) flame spraying with wire, c) plasma spraying, and d) high-velocity oxygen fuel (HVOF) spraying (the most common method of high-velocity flame spraying).

Flame spraying Fuel gas, acetylene-oxygen 3200 50-200 Wire Mostly metals 5-8 metals... 

H. S. Ingham, and A. P. Shepard, Metco Flame Spray Handbook, Volume 1, Wire Process, Metco (Sultzer-Metco), Westbury, New York. 

In flame spraying, the material used for coating (a wire, rod or powder, for instance) is heated in a gas flame until it melts. The molten particles are then transferred to the substrate by the gas jet, and the new surface is generated. In most cases, the surface can be post-treated without difflculty. 

Thermal spraying is the build up of a coating on a substrate from particles sprayed at defined temperature and kinetic energy onto the roll surface. The thermal energy is required to melt the powder particles or the wire while the gas flow is necessary for the particle acceleration. Energy sources can be either electrical (arc, plasma) or chemical H2, propane or kerosene (flame spraying). The melted and accelerated particles hit the surface, re-solidify and build up the coating layer by layer (approx. 10-20 pm/pass). 

For gas combustion processes, the lower-energy flame spray process uses oxyfuel combustible gas as a heat source to melt the coating material, which may be in the form of rod, wire, or powder. In the higher-energy, high-velocity oxyfuel combustion spray (HVOF) technique, internal combustion of oxygen and fuel gas occurs to produce a high-velocity plume... 

There are three basic categories of thermal spray technologies combustion torch (flame spray, high velocity oxy-fuel, and detonation gun), electric (wire) arc, and plasma arc. Thermal spray processes are maturing, and the technology is readily available. 

A group of coating or welding processes in which finely divided metallic or non-metallic materials are deposited in a molten or semi-molten condition to form a coating. The coating material may be in the form of powder, ceramic rod, wire, or molten materials. See also flame spraying and plasma spraying. 

Thermal Spray Flame spray Arc-wire spray Plasma spraying D-gun... 

Thermal spray processing A coating process where material (wire, rod, powder) is melted by a flame, plasma, electric arc, or some other means and the molten particles are propelled in a high velocity gas stream to the substrate surface, where they are splat cooled at a high quench rate. See also Arc-wire spray Detonation flame spraying Flame spray High velocity oxygen fuel (HVOF) spray Plasma spray. 

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