Composite metal objects made by diffusion welding - where parts are immersed in molten salt subjected to high pressure by steam or air

摘要

The metal parts forming the composite are assembled together and immersed in a high temp. melt subjected to pressure so that the parts are forced together and welded. The pressure is pref. created via steam or a gas, esp. compressed air. The melt must not be able to enter the gap between the assembled parts, and such gaps may be sealed before immersing the assembly in the melt. The pref. appts. consists of a pressure vessel contg. the melt and fitted with a heater inside a thermally insulating outer casing. The vessel has a sealed lid via which steam or compressed air is driven into a space above the melt. Used in mfr. objects for aeroplanes, machines, or tubes, where several different metals can be bonded together.