WELDING
1.
It
is the process of joining of two or more pieces of metals by applying heat or
pressure, or both, with or without filler metal to produce a localized union
through fusion or recrystallization across the interface.
2.
Temperature
required for welding is upto 3800 °C.
3.
Metals
to be joined need to be heated till their melting point.
4.
Mechanical
properties of base metal may change at the joint due to heating and cooling.
5.
Welding
joints are the strongest joints.
BRAZING
1.
Brazing
is a process that joins two pieces of base metal when a melted metallic filler flows
across the joint and cools to form a solid bond. The melting point for filler
metal should be more then 450°C but
lower then base metal.
2.
Temperature
may go to 600 °C in brazing.
3.
Metals
are heated but below their melting point.
4.
Mechanical
properties of base metal may change at the joint due to heating but it is
almost negligible.
5.
These
joints are stronger then soldering but weaker then welding.
SOLDERING
1.
Soldering
is very much similar to brazing and its principle is same as that of brazing.
The major difference lies with the filler metal, the filler metal used in case
of soldering should have the melting temperature lower than 450 °C.
2.
Temperature
requirement is upto 450 °C.
3.
No
need to heat base metals.
4.
No
change in mechanical properties of base metals after joining.
5.
These
are the weakest joints out of three.
