Brazing alloys zinc content

In general, the rate of dezincification increases as the zinc content rises, and great care needs to be exercised in making brazed joints with copper/zinc brazing alloys, particularly if they are to be exposed to sea-water. Under these conditions, a properly designed capillary joint may last for some time, but it is preferable to use corrosion-resistant jointing alloys such as silver solders (e.g. BS 1845, Type AGJ or /4G5) . 

Considerable brazing is done by jewelry manufacturers und the solders that are used may be of a lower karat content than the alloy being brazed, Usually they contain much more silver and zinc than (he alloys ihemselves,... 

A soft solder melts at a temperature in the range 200-300°C and consists of a Un-lead alloy. The tin content varies between 80% for the lower end of the melting range and 31% for the higher end. Hard solders contain substantial quanUUes of silver in the alloy. Brazing solders are usually alloys of copper and zinc, which melt at over 800°C. 

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