Fronius International, a welding technology company, has evolved its proven Cold Metal Transfer (CMT) weld process a stage further. A new algorithm now makes it possible to use this advanced process in fields of application that had always been entirely, or largely, the preserve of globular and pulsed arcs. A number of newly developed characteristics make for ease of operation and help users achieve superlative welding results. Previously supplied systems can be upgraded at no extra cost.

By developing the new algorithm, the Fronius developers have revisited the forward-and-back motion of the wire electrode that is so typical of the CMT process, and boosted its frequency to as much as 130 Hz. Besides this, the welding specialists have also re-engineered the current-profile of the characteristics. Depending on the filler metal and wire diameter, this enables the operating limit of the CMT process to be raised by up to 40 per cent.

One of the new characteristics is called 'Universal'. It has been designed for all standard applications, and stands out for its good gap-bridging ability. For applications requiring greater penetration and welding speed, Fronius has developed the 'Dynamic' characteristic. As its name suggests, the new characteristic 'Root' is especially suitable for root welding, making it ideal for use in, e.g., pipeline construction. These redrawn performance boundaries give CMT users a huge number of characteristics for many different filler metals and areas of application.

The higher deposition rate and energy density in the arc phases of the new CMT characteristics increase the penetration depth and permit higher welding speeds, yet with CMT's same accustomed process stability. Thanks to the higher welding speed, the energy per unit length drops to a level that is considerably below that of a globular or pulsed arc. This means that even fillet-welded joints on thicker sheets, for example, can now be welded without difficulty.

A large number of companies in the automobile industry, in mechanical engineering and plant construction and in many other industries are already profiting from the advantages of the CMT process in both one-off and series production. Recent and future advances in the CMT weld process will encourage even more widespread adoption of CMT.

Fronius International is an Austrian company active in the fields of battery charging systems, welding technology and solar electronics.