Aluminium soldering composition

DETAILED DESCRIPTION OF THE INVENTION Fluxed solder compositions and, in particular, flux-cored solder compositions are known.
Fluxed solder compositions permit the introduction of both flux and alloy to the area of the joint site co-operatively and simultaneously and in constant proportions of flux to solder.
They are commonly formed of a solder alloy and have associated therewith a quantity of a soldering flux, the arrangement being such that when the fluxed solder composition is applied to the joint site in the soldering process, the flux associated therewith flows progressively onto the joint site as the solder alloy of the fluxed solder composition is consumed, i.
e.
melted and solidified during the process.
The fluxed solder composition is conveniently provided as an elongate member having a substantially uninterrupted core, or plurality of separate cores, of the flux, which core or cores extend longitudinally through the interior (as distinct from the surface) of the solder alloy.
Fluxed solder compositions of this convenient form are herein referred to as flux-cored solder compositions.
However, it should be understood that a fluxed solder composition can be constituted by an elongate member of the solder alloy coated with a quantity of the soldering flux or by an intimate mixture of a flux and a solder powder, the mixture being, for example, a dimensionally stable solid or even a paste or cream in the range of normal room temperatures.
Flux-cored solder compositions may be made by extruding the solder alloy so as to form an elongate wire rod while simultaneously introducing flux cores into cavities in the wire or rod.
The diameter of the extruded wire or rod may then be reduced by, for example, rolling or drawing.
Where reference is made herein to the melting point of an alloy, this should be understood to refer to the liquidus temperature of that alloy.
The proportions of the elements contained in the soft solder alloy are expressed in this specification as percentages by weight of the alloy