National Research Development Corporation

Sprayforming Developments Limited

Walter N Jenkins

Alfred R Singer

Gordon I Davies

Asgar M Alibhai

Apparatus for scanning a stream of atomized particles having externally

Metal spraying apparatus

Spray deposition of metals

For uniformly coating a substrate with a spray, a stream of liquid falls past a point towards which a plurality of nozzles in a bank are all directed but at different angles. Bursts of atomising gas are sprayed through the respective nozzles in a repeated sequence, such as to cause a repeated sequence of equal durations of spray in a plurality of directions.

Producing directed spray

Aluminum is flow-coated onto ferrous strip by reducing the hot strip in hydrogen, cooling it to 650.degree.-680.degree. C. in nitrogen and spraying molten aluminum on it such that the aluminum splats flow into each other but solidify in 0.2-0.5 seconds. The aluminum is bonded to the strip through an intermetallic layer less than quarter of the total coating thickness, the aluminum having a cast structure.

Flow coating of metals

A liquid stream 2 from a nozzle 1 is atomized and distributed over a substrate 3. The liquid falls into a downwardly angled chute 10 formed by strong gas jets focussed to a point X. An air-knife 20 directed vertically downwardly in the plane of X atomizes the liquid. Gas-knives 12 and 13 are fired alternately and apply equal but opposite deflections to the liquid, which however remains in the plane of 20. The liquid is then evenly distributed on the substrate 3, which is advanced intersecting the plane of 20.

Method of distributing liquid onto a substrate

Metal from strip feedstock 3 is arc-deposited onto a substrate 1, being propelled when molten by a gas curtain from a slit 13. The feedstock 3 is melted in regular fashion by an arc 11 struck between it and a helical non-consumable electrode 9 rotated on its axis, which is parallel to the leading edge of the feedstock 3. As the electrode 9 rotates, the arc 11 must move along the helix to keep its shortest path, and hence is constrained to traverse the full width of the feedstock 3 repetitiously.

Growing community of inventors

Wales, United Kingdom

Walter N Jenkins