EP0051869A1
Expired / Lapsed
EP
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Improvements relating to methods of spraying metallic coatings and apparatus for use in the spraying of metallic coatings
Assignee: Metallisation Ltd
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Filing: 1981-11-06
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Granted: —
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Expires: 2001-11-06
Abstract
Abstract The surface of a workpiece is coated with a metallic material by the use of a spraying device in which an electric potential is applied across two metallic wires (W1, W2) to establish an arc therebetween, the wires being progressively advanced towards the arc as they are melted by the arc. Gas under pressure is fed towards the arcing zone, the gas including a carrier stream to cause molten metal droplets produced by the arc to be carried away from the arcing zone towards the surface to be sprayed, and optionally one or more supplementary streams such as may be operative to constrain the carrier stream to a desired (e.g. conical) shape. In accordance with the invention, one or more of the streams of gas includes, or is provided by, a modifying agent, afforded by a substance or composition which is effective to modify the coating sprayed onto the workpiece, compared with the coating produced by the use solely of air. The modifying agent may produce a chemically or physically modifying effect in relation to the conditions pertaining at or in the vicinity of the arcing zone, and/or a chemically or physically modifying effect in relation to the coating sprayed onto the workpiece.
Inventors
- 👤 Stewart John Ashman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 08:54
CPC Classifications
B; B05; B05B; B05B7/00; B05B7/16; B05B7/22; B05B7/222; B05B7/224; C; C23; C23C; C23C4/00; C23C4/12; C23C4/131
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
134 words
A method of spraying a coating of a metallic material onto a surface, utilising a metal spraying device in which an electric potential is applied across two metallic wires to establish an arc therebetween, the wires being progressively advanced towards the arc as they are melted by the arc, gas under pressure being fed towards the arcing zone, such gas including a carrier stream to cause molten metal droplets produced by the arc to be carried away from the arcing zone towards the surface to be sprayed, and optionally one or more supplementary streams such as may be operative to constrain the carrier stream to a desired shape, in which the or one of the streams of gas fed towards the arcing zone includes, or is provided by, a modifying agent other than air.
Claim 2
Independent Claim
134 words
A method of spraying a coating of a metallic material onto a surface, utilising a metal spraying device in which an electric potential is applied across two metallic wires to establish an arc therebetween, the wires being progressively advanced towards the arc as they are melted by the arc, gas under pressure being fed towards the arcing zone, such gas including a carrier stream to cause molten metal droplets produced by the arc to be carried away from the arcing zone towards the surface to be sprayed, and optionally one or more supplementary streams such as may be operative to constrain the carrier stream to a desired shape, in which the or one of the streams of gas fed towards the arcing zone includes, or is provided by, a modifying agent other than air.
Claim 3
Dependent Claim
20 words
A method according to Claim 1 wherein the modifying agent is effective to modify the temperature of the arcing zone.
Claim 4
Independent Claim
21 words
A method according to one of Claims 1 and 2 wherein the modifying agent is effective to modify the arcing atmosphere.
Claim 5
Independent Claim
30 words
A method according to any one of Claims 1, 2 and 3 wherein the modifying agent is operative to modify the coating obtained by the use of the spraying device.
Claim 6
Independent Claim
29 words
A method according to any one of the preceding claims wherein the modifying agent is in gaseous, or liquid, or solid form, or a combination of any of these.
Claim 7
Independent Claim
23 words
A method according to any one of Claims 1 to 5 wherein the modifying agent is included in or provides the carrier stream.
Claim 8
Independent Claim
27 words
A method according to any one of Claims 1 to 6 wherein the modifying agent is included in or provides one or more of the supplementary streams.
Claim 9
Dependent Claim
103 words
A method according to Claim 1 wherein the modifying agent is selected from one or more of the following:- (a) reducing agents in gaseous, liquid or solid powder form; (b) oxidizing agents in gaseous, liquid or solid powder form; (c) combustible gases; (d) hydrogen peroxide; (e) water; (f) ceramic materials in finely divided form; (g) metallic materials in finely divided form; (h) metallic fillers in finely divided form; (i) metallic carbides in finely divided form; (j) metallic borides in finely divided form; (k) metallic oxides in finely divided form; (1) copper alloys in finely divided form; (m) plastics materials in finely divided form.
Claim 10
Dependent Claim
191 words
Apparatus for use in the spraying of a metallic coating, comprising a body (6), feeding mechanism (50) for simultaneously feeding two metallic wires (W1, W2) or rods through two guide passages (62) which converge forwardly in the direction of wire feed, connecting means which may be connected to a supply of electricity to cause an arc to be established between the wires (W1, W2) where they emerge from the guide passages (62) so as to melt the wires, first delivery means (18, 34, 60) for delivering a stream of gas under pressure to the arcing zone so as to cause molten metal droplets to be carried away from the arcing zone on the carrier stream from the device towards the surface to which a coating is to be applied, and second delivery means (110, 124; 114, 118) to deliver a stream of gas under pressure towards the vicinity of the arcing zone, to constrain the carrier stream to a desired shape, the first and second delivery means being separate, whereby modifying agents may be added to, or may provide one of, said streams of gas under pressure separately from the other.
Claim 11
Dependent Claim
191 words
Apparatus for use in the spraying of a metallic coating, comprising a body (6), feeding mechanism (50) for simultaneously feeding two metallic wires (W1, W2) or rods through two guide passages (62) which converge forwardly in the direction of wire feed, connecting means which may be connected to a supply of electricity to cause an arc to be established between the wires (W1, W2) where they emerge from the guide passages (62) so as to melt the wires, first delivery means (18, 34, 60) for delivering a stream of gas under pressure to the arcing zone so as to cause molten metal droplets to be carried away from the arcing zone on the carrier stream from the device towards the surface to which a coating is to be applied, and second delivery means (110, 124; 114, 118) to deliver a stream of gas under pressure towards the vicinity of the arcing zone, to constrain the carrier stream to a desired shape, the first and second delivery means being separate, whereby modifying agents may be added to, or may provide one of, said streams of gas under pressure separately from the other.
References Cited (Backward Citations)
FR516567A
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US2003167A
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DE811899C
Cited
GB899275A
Cited
DE1813349A1
Cited
GB1277488A
Cited
WO1980000544A1
Cited
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