8
Gas Welding, Brazing and Soldering
Brazing
Self-fluxing Classification AS / NZS 1167.1–B4
ProSilver 15
Chemical Composition, wt% Silver Phosphorous Copper
Self-fluxing for pure copper brazing due to the action of phosphorous; copper alloys, like brasses and bronzes, will require additional fluxes. It is not suitable for steel or alloys containing more than 10% nickel. It produces rough-textured fillets of a greyish colour and, when permitted to run uncontrolled over the work, will roughen the surface. Not recommended where good appearance is desired or where subsequent electroplating is necessary. The alloy has a relatively wide melting range and the parent metals brazed almost always have high thermal conductivity. For these reasons, the work should be heated quickly to brazing temperature and oxy-acetylene is preferable to either natural gas or propane. Brazing of tough pitch copper should be carried out with a slightly oxidizing flame to avoid hydrogen embrittlement. Due to its wide melting range, there is a tendency for low melting phases to run out of the joint if the heating rate is too low, so care has to be taken to heat quickly to the brazing temperature. ProSilver 15 is used for high vibration joints on refrigerator copper pipes. It is also used for brazing contacts onto copper-based parts because of its good flow characteristics and good electrical conductivity.
14.50–15.50 4.50–5.50 Balance
Physical Properties Density Solidus Liquidus Brazing Temp.
7.5 g / cc 645°C 800°C 700–820°C
Application Suitable Flux
Tenacity 4A No flux required for pure copper 0.05–0.2 mm
Optimum Joint Gap Packaging Data Wire Size (mm)
Pack Size
Part No.
1.5 x 750 3.0 x 750 1.5 x 750 3.0 x 750
1.0 (kg) 1.0 (kg) Single rod Single rod
LTAP1550 LTAP1513 LTAP1551 LTAP1598
It is not recommended for use in shock-loading situations, sulphurised gas or marine environments.
WARNING Welding can give rise to electric shock, excessive noise, eye and skin burns due to the arc rays, and a potential health hazard if you breathe in the emitted fumes and gases. Read all the manufacturer’s instructions to achieve the correct welding conditions and ask your employer for the Materials Safety Data Sheets. Refer to www.boc.com.au or www.boc.co.nz
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NZ : IPRM 2007 : SECTION 8 : CONSUMABLES