Soldering and brazing are metal joining processes where a filler metal is melted and drawn between closely fitted metal pieces through capillary action to form a permanent bond. Brazing differs from soldering in that the filler metal has a higher melting point above 450°C, while soldering uses filler metals with lower melting points. Common brazing methods include torch, furnace, dip, and induction brazing, while soldering is typically done with an iron or through wave soldering of printed circuit boards. Brazing and soldering offer advantages over welding like joining dissimilar metals, lower temperatures, less distortion and damage, and faster joining.

1. Abdulrahman Aziz AlAnazi
Saud Ghanem AlAnazi
Dr. Mahmoud Tash

2. Introduction
 Soldering and brazing
provide permanent joint
to bond metal pieces.
 Soldering and brazing
process lie some where
in between fusion welding
and solid state welding.

3. Brazing
 In case of brazing joining of metal pieces is
done with the help of filler metal.
 Filler metal is melted and distributed by
capillary action between the faying surfaces
of the metallic parts being joined.

4. Brazing
 In this case only filler metal melts, there is no
melting of workpiece metal.
 The melting point of filler metal should be
more than 450oC.

5. Brazing Process
 The filler metal is drawn
through the joint to create this
bond is capillary action. In a
brazing operation, you apply
heat broadly to the base
metals. The filler metal is then
brought into contact with the
heated parts. It is melted
instantly by the heat in the
base metals and drawn by
capillary action completely
through the joint.

6. Brazing Methods
 Torch brazing - flux is applied to the part
surfaces and a torch is used to focus flame
against the work at the joint. A reducing flame
is used to prevent the oxidation.
 Furnace brazing - used to heat the workpieces
to be joined by brazing operation. The
component parts and brazing metal are
loaded into a furnace, heated to brazing
temperature, and then cooled and removed.

7. Brazing Methods
 Dip brazing - assembled parts are typically
dipped in a heated chemical bath which serve
as both fluxing agent and heat source to melt
pre-applied filler material.
 Induction brazing – a process that uses
electrical resistance of workpiece and high
frequency current induced into the same as a
source of heat generation. The parts are pre-loaded
with filler metal and placed in a high
frequency AC field.

8. Soldering
 Soldering is very much similar to brazing.
 The major difference lies with the filler metal,
the filler metal used in case of soldering
should have the melting temperature lower
than 450oC.

9. Soldering
 Soldering is normally done by melting the solder
with a soldering iron and applying it to the two
metals that are going to be joined together.
 The filler metal used in the process is called solder,
which distributes between the closely fitted
surfaces.

10. Soldering Methods
 Iron soldering - The oldest and simplest
soldering method and is still widely used
today. Soldering irons have copper tips which
easily stores and transfers heat to the joint.
 Wave soldering -A specific method used in the
fabrication of electronic components and
printed circuit boards (PCB). In this method,
continually circulating fountains or waves of
solder are lifted into contact with the joints.

11. Filler Metals
 Brazing : Aluminum-silicon ,Copper, Copper-phosphorus,
Magnesium, Silver, Nickel alloys.
 Soldering : combinations of tin-lead, tin-silver-lead,
tin-zinc, silver-copper-zinc and zinc-aluminum
alloys.

12. Advantages of Brazing & Soldering
 Joining dissimilar metals and
non-metals.
 Low temperature compared
to welding.
 less thermal distortion.
 Less chance of damage
 Speed of joining.
 Less manual skills.

13. Disadvantages of Brazing &
Soldering
 Low strength. .
 damaged under high
temperature condition .

14. Summary
Brazing and soldering are process that have many
great advantages that are often overlooked.
They are an excellent process for portable
applications and the versatility makes them great
choices for many jobs.
Their ability to join may different materials with a
limited variety of fluxes and filler metals reduces
the need for a large inventory of materials.