Colder arc welding
FRONIUS, represented in Australia by Paul England & Staff , has released a cold metal transfer (CMT) process offering an alternative to automated or robot-assisted GMA processes for the joining of thin metal sheets.
Workpieces and weld zones remain considerably colder than with conventional gas metal arc (GMA) welding. Users can butt weld or braze sheets over 0.3mm thick. The process selectively breaks off or breaks up the arc. The movement of the wire is built into the welding process and its control system resulting in spatter-free metal transfer.
Each time the short-circuit occurs with a frequency up to 70Hz, the digital process control interrupts the current supply on one hand and controls retraction of the wire on the other. This wire retraction movement assists droplet detachment during short-circuiting. The current and consequently the heat input into the materials to be joined are reduced significantly as a result of the controlled interruption of short-circuiting.
14-Oct-2004