Brazing aluminium@ (alloys) under vacuum - using filler metal without getter effect and coating components with titanium@ (alloy) before brazing

摘要

A method is claimed for the brazing under vacuum of aluminium (alloys) with the interposition of a classical filler metal. Before bringing the components to be brazed together they are coated with a layer of Tp (alloy) with a thickness of 1-10 microns, pref. 5 microns, after cleaning their surfaces of appropriate pickling such as ionic pickling. The components are then put in contact in a furnace enclosure under vacuum together with the filler metal in the form of a film or a powder or a wire or other appropriate form. The vacuum applied is less than 1.33 x 10 power-2 Pa and is preferably 1.33 x 10 power-3 Pa. Magnesium may be introduced to the furnace enclosure prior to the brazing operation. The filler metal used is pref. an aluminium silicon alloy that is not subjected to the getter effect during the thermal cycle of brazing under vacuum. USE/ADVANTAGE - The method is used for the brazing under vacuum of aluminium and it alloys, preferably without getter effect in the furnace enclosure. The method allows the use of less elaborate vacuum than for conventional methods of brazing and produces joints with a very good metallurgical soundness, without contaminating the furnace used for the brazing operation.