Abstract: Apparatus for the production of powders or spray deposits is provided in which a metal or metal alloy stream is broken up into atomized droplets by primary jets of atomizing gas. In order to remove further heat from the atomized droplets, secondary jets are positioned adjacent the primary jets for directing cooling fluid in the form of cryogenic liquified gas at the atomized droplets. The apparatus permits the formation of coarser powders, powders from alloys with a wide solidus/liquidus gap in a shorter atomizing chamber, or spray deposits with increased yield of deposited material.

Abstract: A device for gas atomising a liquid stream, such as a stream of molten metal or metal alloy, has an atomising device including, for example, an annular opening for receiving the stream. The atomising device is arranged for applying atomising gas to the stream so as to form a spray of atomised particles. At least a part of the atomising gas, and preferably all, is applied by means movable relative to the stream whereby movement is imparted to the spray to achieve improved uniformity or control of deposition by moving the spray either by moving the atomising device with a symmetric gas flow field relative to the stream or by oscillating or rotating a rotor mounted within the atomising device and arranged to produce an asymmetric gas flow field.