1. presented by, ARAVIND PV ME S4 NO 59
welcome
TOPIC
FILLER MATERIALS FOR BRAZING
presented by,
ARAVIND PV
ME S4
NO 59

2. brazing
Brazing is a metal joining process in which two or more metal items are joined together by melting and flowing a filer metal into the joint. The filler metal also called “spelter” having a lower melting point than the adjoining metal.

3. FILLER MATERIALS
A variety of alloys are used as filler metals for brazing depending on the intended use or application method. In general braze alloys are made up of 3 or more metals to form an alloy with the desired properties. The filler metal for a particular application is chosen based on its ability to. Wet the base metals, withstand the service conditions required, and melt a lower temperature than the base metals or at a very specific temperature. Braze alloy is generally available as rod, ribbon, powder, paste, cream, wire and preforms.

4. Depending on the application the filler metal can be preplaced at the desired location or applied during the heating cycle. For manual brazing, wire and rod forms are generally used as they are the easiest to apply while heating, in the case of furnace brazing, alloy is usually placed beforehand since the process is usually highly automated.

5. Some common type filler metals
Pure metals
unalloyed. often noble metals silver gold palladium
Silver copper (Ag-Cu)
good melting properties, silver enhances flow. Eutectic alloys used for furnace brazing. Copper rich alloys prone to stress cracking by ammonia.
Silver zinc (Ag-Zn)
Used in jewelry due to its high silver content so that the product is compliant with hallmarking. The color matches silver, and it is resistant to ammonia containing silver cleaning fluids.

6. Brass (Cu-Zn)
general purpose, used for joining steel and cast iron. Corrosion resistance usually inadequate for copper, silicon bronze
Silver copper zinc (Ag-Cu-Zn)
lower melting point than Ag-Cu and Cu-Zn
Silver copper phosphorus (Ag-Cu-P)
Copper phosphorus (Cu-P)
Gold silver (Au-Ag)
Gold copper (Au-Cu)
Gold nickel (Au-Ni)
Gold palladium (Au-Pd)
Aluminium silicon (Al-Si)
Active alloys (titanium, vanadium)
used for nonmetallic materials eg:- graphite or ceramics