Citation:
C.G. Pickin, S.W. Williams, M. Lunt, Characterisation of the cold metal transfer (CMT) process and its application
for low dilution cladding, Journal of Materials Processing Technology, Volume 211, Issue 3, 1 March 2011, Pages 496–502.
Abstract:
The process characteristics of the synergic cold metal transfer (CMT) process
have been examined for welding aluminium alloy. Utilising a simple backlighting
system and through the arc monitoring the droplet transfer modes were
identified. Whilst the modified short circuit mode was evident for the lower
parameter range, a two part transfer mode based upon a combination of spray and
short circuit transfer was observed for the mid to upper parameter range. The
technology was also explored as a cladding process for applying to ternary
alloyed (Al–Cu–Mg) aluminium plate. This alloy system is known to be susceptible
to solidification cracking when MIG welded using the binary Al-2319 (Al–Cu)
filler wire, this being due to the wide element freezing range of the weld
resulting from mixing with the base material. Utilising this filler, weld
dilution ratios for both CMT and pulsed welding were identified across the
examined parameter range. The CMT process exhibited greater control of dilution
that enabled deposition of a quasi-binary (Al–Cu) layer exhibiting a less crack
susceptible composition. Onto this layer conventional MIG welding could be
applied which could potentially eradicate cracking using a binary fil
