Abstract: A method of producing a 3D article by additive manufacture is provided. The method includes the steps of: forming a meltpool in an already-existing part of the article, and moving the meltpool relative thereto; feeding a directed feedstock into the moving meltpool to deposit and fuse a layer of material on the already-existing part; and repeating the forming and moving and feeding steps to build up successive layers of material. In performance of the forming and moving step: a first energy source impinges at a first region of the already-existing part which moves with and leads the meltpool, whereby the first energy source initiates the formation of the meltpool; and a second energy source impinges at a second region on the already-existing part which moves with and follows the first region, whereby the second energy source grows the lateral width of the meltpool before the feedstock is fed therein.

Abstract: A coolant delivery device (100) comprises a coolant outlet (124) and an exhaust (140, 160). The coolant outlet (124) is contained within a housing (150) that has an opening provided with sealing means (180), to which opening the coolant outlet (124) is arranged to direct a coolant. In use of the device, coolant is delivered to a surface to be cooled, and the coolant vaporises at the surface so as to produce coolant gas. Since the sealing means (180), in use of the device, form a seal between the housing (150) and the surface, the coolant gas is constrained to escape the device through the exhaust (140, 160), and does not disturb or disrupt the ambient environment. The device is particularly useful for applying thermal tensioning to welds through the delivery of a cryogenic spray to a weld line.