Additive manufacturing, commonly known as 3D printing, is a hot topic at the moment. An increasing range of components and goods, including those made from metal, are being produced quickly and inexpensively using additive methods, such as wire arc additive manufacturing (WAAM). This arc process offers significant advantages in terms of time and cost for a variety of different applications. The “cold” Fronius welding process, CMT, is particularly suitable here.

Additive manufacturing processes allow users to practically conjure up components out of thin air – in fact, layers of liquid or powdered material are gradually built up on a base plate. With WAAM, this is carried out using a consumable wire electrode – the process itself being based on arc welding. Generative manufacturing techniques are particularly suited to producing complex component geometries. In addition, parts can be manufactured at low cost and extremely quickly – which makes WAAM a very attractive option for prototype construction and small batches. The processing time, tool wear, and material loss are all considerably lower than when milling out the workpiece from a solid block.

“COLD” WELDING PROCESS ACHIEVES OPTIMUM RESULTS

The stability of the welding process and heat dissipation are crucial factors when manufacturing components using WAAM. The welding process must apply as little energy as possible, so that the lower layers do not begin to melt again. The welded layers must also be consistent, spatter-free, and even. If any flaws were to occur, these would be replicated in each subsequent layer. The “cold” welding process from Fronius, Cold Metal Transfer (CMT), meets all of these requirements.

Two process control variants of CMT are particularly well suited to WAAM. The first of these is the CMT additive process characteristic, which has been optimized for WAAM. It achieves good deposition rates and only transfers a low level of heat to the component. The CMT Cycle Step variant reduces the arc power even further using targeted deactivation during the process phase. However, more time is needed to build up the individual layers as the deposition rate is lower.