Thermal Joining of Metals
14
Thermal Joining of Metals By Dom G
description
By Dom G. Thermal Joining of Metals. Fusion Welding. Fusion welding involves a heat source. It may also involve the use of a filler material such as a consumable electrode or a wire. - PowerPoint PPT Presentation
Transcript of Thermal Joining of Metals
Thermal Joining of Metals
By Dom G
Fusion Welding
Fusion welding involves a heat source. It may also involve the use of a filler
material such as a consumable electrode or a wire.
These processes also use a protective layer between the atmosphere and the molten metal, either in the form of gas shielding or a flux.
There are several different types of fusion welding processes that can be used.
Oxyacetylene
Oxyacetylene welding is a process which uses a combination of oxygen and acetylene.
When mixed together the hand-held torch produces a flame with temperatures of around 3,200 – 3,500 degrees Celsius.
The chemical action of the oxyacetylene flame can be adjusted by changing the ratio of the volume of oxygen to acetylene.
Oxy Acetylene
Manual Metal Arc (MMA) Manual Metal Arc Welding is a process that
uses a flux coated, consumable electrode to produce a weld.
An electric arc must be created, and there for a current must be applied, either AC or DC can be used.
As the weld is being laid the flux gives off a gas which serves as the shielding gas.
This process is extremely versatile and simple to use and is therefore a popular technique to use.
Tungsten Inert Gas Welding (TIG) TIG is an arc welding process that uses a
nonconsumable tungsten electrode to produce the weld.
Argon is usually used to shield the weld from atmospheric gases.
TIG welding is often used on Aluminium and similar light materials such as Magnesium or Copper Alloys.
This process produces a high quality weld, but is a complex method and hard to master.
MIG
MIG is a semi-automatic process of welding
A constant, nonconsumable wire electrode and shielding gas are fed through the welding gun.
A current must be used in MIG welding and AC or DC current can be applied.
MIG welding is a fast process which is easy to produce compared to that of TIG welding.
MIG(1) Torch handle, (2) Molded phenolic dielectric (shown in white) and threaded metal nut insert (yellow), (3) Shielding gas diffuser, (4) Contact tip, (5) Nozzle output face
(1) Direction of travel, (2) Contact tube, (3) Electrode, (4) Shielding gas, (5) Molten weld metal, (6) Solidified weld metal, (7) Workpiece
Soft Solder Soldering is a process where two or more metals
are joined together by melting and flowing a filler metal a joint.
Soft soldering has a melting point of the filler metal, which is below 400 °C.
In the process of soldering, heat is applied to the parts of material to be joined, causing the solder to melt and be drawn into the join by capillary action.
The main applications for this technique are joining components to circuit boards and joining copper pipes for plumbing.
Soft Solder
Hard Solder
Hard solders are used for Brazing, and melt at higher temperatures of around 900 °C.
Copper mixed with zinc or silver are the most common alloys used.
Generally hard solder produces a stronger joint than soft solder.
There are various hard solders that a produced at different temperatures and vary in hardness.
References and Sources
http://www.twi.co.uk/content/jk3.html
http://en.wikipedia.org/wiki/TIG http://en.wikipedia.org/wiki/Manual_
metal_arc_welding
