Abstract: Metallic articles having heat transfer channels are produced by solidification of molten metallic material about pre-formed channel defining members such that a solidified metallic deposit having heat transfer channels is formed. The channel defining members may be in the form of either solid elements (which are subsequently removed to leave the channels), or conduit elements (which may remain permanently embedded in the article). Moulds, dies, cores and other tools for use in moulding or casting of plastics and metals are particularly suitably formed by the process, the heat transfer channels being used for cooling of the respective articles during use. The molten metallic material is preferably deposited by spray forming utilizing one or more sprays of molten metallic material.

Abstract: A stream of gas atomized particles moves past a secondary gas stream towards a substrate. The secondary stream is directed in an oscillatory manner against the stream of atomized particles to deflect the latter such that the particles are distributed in a controlled manner over the surface of the substrate.

Abstract: Apparatus for the spraying of atomized particles, which comprises means for producing a stream of gas atomized particles, means for directing a secondary stream of gas against the stream of gas atomized particles and control means adapted for repeated cyclic operation for varying the secondary stream of gas in such a manner as, in operation, to deflect the stream of gas atomized particles and impart thereto an oscillation substantially in a single plane. There is also included a process for spraying atomized particles which comprises producing a stream of gas atomized particles and directing a secondary stream of gas against the stream of gas atomized particles in such a manner as to deflect the stream of gas atomized particles and impart thereto an oscillation substantially in a single plane.