Advanced Welding Processes: Technologies and Process Control

2
Advanced welding processes
A union between two pieces of metal rendered plastic or liquid by heat or
pressure or both. A filler metal with a melting temperature of the same order
as that of the parent metal may or may not be used. [1]
or alternatively:
A localized coalescence of metals or non-metals produced either by heating
the materials to the welding temperature, with or without the application of
pressure, or by the application of pressure alone, with or without the use of
a filler metal. [2]
Many different processes have been developed, but for simplicity these may
be classified in two groups; namely ‘fusion’ and ‘pressure’ welding as shown
in Fig. 1.1, which summarises some of the key processes. A more extensive
list of processes is reproduced in Appendix 1. [1]
1.2 Conventional welding processes
A brief description of the most common processes, their applications and
limitations is given below. The more advanced processes and their developments
are dealt with in more detail in the remaining chapters.
An international standard ISO 4063 [3] identifies processes by a numeric
code. The first digit of this code specifies the main process grouping whilst
the second and third digit indicate sub-groups. The main groups and some
Welding processes
Welding with pressure Fusion welding
Cold pressure
Resistance welding
Friction welding
Diffusion bonding
Explosive welding
Magnetically impelled
arc butt welding
1.1 Some important welding processes.
Manual metal arc
welding
Gas tungsten arc welding
Gas metal arc welding
Submerged arc welding
Laser welding
Electron beam welding