Wire arc AM (WAAM)

This new process adapts time-proven arc welding and plasma arc welding tools and wire to the specific requirements of additive manufacturing. Gas-metal arc welding (MIG/MAG) and plasma welding techniques are used to melt metal filler to form a 3D component layer by layer.

The wire arc AM process

As in standard MIG/MAG welding, metal wire is added as the electrode melts in the arc and its droplets form layers on the substrate. Processes with lower heat input, such as controlled short-circuit metal transfer, are preferred given the heat sensitivity of most materials used in additive manufacturing. Shielding gases protect the layers against ambient air.

Advantages of arc and plasma additive manufacturing:

• With no complex tooling or equipment needed, investment costs are low
• The end-product benefits from greater structural integrity and less distortion
• The ability to produce lightweight components from costly materials like aluminium and titanium without material waste makes arc and plasma additive manufacturing interesting for many industries, in particular for aerospace, automotive or medical
• More cost-effective than other additive manufacturing processes like laser beam welding and electron beam welding.

Shielding gases in arc and plasma additive manufacturing processes 

Air, hydrocarbons and moisture will lead to distortion. To avoid the chemical reaction experienced by heated metal when in contact with elements like oxygen and nitrogen, gases are applied to protect the hot substrate against the ambient atmosphere. This protective shield of gas ensures that the quality of the weld joint is not marred by the chemical reaction. The metallurgical properties of the component are maintained or in some cases even improved when deoxidisers are added to the weld.

Tried-and tested MIG/MAG welding gases help improve mechanical properties 

Argon, helium and mixtures of both are the preferred process gases for MIG/MAG welding and plasma additive manufacturing. Active components such as CO₂, O₂, N₂ or H₂ can be added to fine-tune material properties. With its long-standing expertise in all welding, cutting, heating and surfacing applications, BOC can help you choose the right gases and mixtures for your arc and plasma additive manufacturing projects. 

We deliver a range of tried-and-tested MIG/MAG welding gases under our ARGOSHIELD, PURESHIELD, SPECSHIELD and STAINSHIELD products. These mixes have been designed to enable you to combine the benefits of automatic welding, which include continuity, speed, comparative freedom from distortion and reliability, with the versatility and control of manual welding.

BOC solutions for arc processes at a glance:

• Argon and helium gas supply – design, provision and installation
• Active gas supply – gases mixed in advance or on-site satisfying specific process demands
• Plasma gases – required to generate the plasma
• On-site support – process and/or technical support
• On-stream gas system – design and maintenance services
• Gas safety – equipment, safety checks and training.