MIG - Metal Inert Gas
MAG - Metal Assisted Gas
CMT - Cold Metal Transfer (see image above)
CMT (Cold Metal Transfer) is a modified short-circuit MIG (Metal Inert Gas) welding process which uses rapid power regulation synchronised with oscillating wire electrode motion. The motion of the wire electrode is unique to the CMT process as it is not only feeds into the workpiece but also retracted, this retraction of the wire for the workpiece assists the transfer of material from electrode to the weld.
Typically it is 30% less heat input when compared to standard MIG processes. The wire motion operates at a frequency of up to 70Hz, each CMT cycle takes 14ms. The reduced heat input characterised by the CMT process enables it to be applied to thin sheet materials which previously welding with MIG was not thought feasible. It is also possible to join steel and aluminium with the CMT process. The CMT process has a very ‘soft’ and stable arc during welding, meaning each joint is practically splatter free. When compared to standard or pulsed MIG processes CMT is considerably colder and cleaner.
- Higher gap / fit-up tolerence
- Practically splatter free
- Allows joining of dissimilar metals (e.g. aluminium to coated steel)
- Single-sided process enables improved flexibility of product design:
- Part flange widths can be reduced (from circa 18mm to 7mm)
- Can be used to weld closed structures (sheet to tube etc.)
- Improved dimensional stability:
- Lower overall thermal input to the part compared with MIG processess
- Non-force applying process
- Reduced energy consumption