Cold Metal Transfer Process Research Articles

Puls-Mix — a new process in arc welding

Welding processes that are as spatter-free as possible improve quality and productivity when joining sheet metal. The CMT (Cold Metal Transfer) process from Fronius fulfils these requirements almost to the letter. There is, however, a limit to its performance. The new Puls-Mix process combines the CMT and pulsed-arc welding processes. The user can now enjoy the relatively high power correction limit of pulsed-arc welding and near-CMT quality.

Investigation of Microstructure and Mechanical Properties of Steel‐Aluminium Joints Produced by Metal Arc Joining

Joints of zinc coated steel (DX54D+Z200) to aluminium alloys (AW6181‐T4 and AW5182‐H111) were produced by the Cold Metal Transfer (CMT) technique, a modified metal inert gas (MIG) joining process. The aluminium alloy sheets and the AISi3Mn1 filler material are welded, while brazing occurs between the AISi3Mn1 filler and the steel sheet. At the interface between the Al‐based filler and the steel sheet, aluminium‐rich intermetallic FexAly‐phases are formed. The comparatively low heat input of the CMT process and the choice of filler composition limit the thickness of the intermetallic phase seam (IMP) to a few micrometers. The structure of the intermetallic phase and its morphology are strongly influenced by the alloying elements (Mn, Si) of the filler. Tensile tests and crash tests of the steel to aluminium alloy joints revealed good mechanical properties.

The arc characteristics and metal transfer behaviour of cold metal transfer and its use in joining aluminium to zinc-coated steel

Cold metal transfer (CMT) is a modified metal inert gas welding process based on short-circuiting the transfer process, characterised by low heat input and no-spatter welding. The arc characteristics and its droplet transfer process have been studied by high-speed video photography. The process was used to join aluminium to zinc-coated steel. The results shows that no-spatter welding and low heat input during the welding process can be realized by CMT, and a dissimilar metal joint with good performance can be obtained by the CMT process.

Evaluation of cold metal transfer (CMT) process for welding aluminium alloy

Cold metal transfer (CMT) is an automated welding process based on dip transfer welding, characterised by controlled material deposition during the short circuit of the wire electrode to the workpiece. Preliminary results are presented examining the suitability of this process for welding aluminium alloy. Trials show that in comparison with pulsed metal inert gas (MIG) welding, CMT exhibits a higher electrode melting coefficient. By adjusting the short circuit duration penetration can be controlled with only a small change in electrode deposition. Furthermore, by mixing pulsed MIG welding with CMT welding the working envelope of the process is greatly extended allowing thicker material sections to be welded with improved weld bead aesthetics.