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The rise of the additive manufacturing industry has pushed the limits of traditional arc welding processes. To meet today’s elaborate requirements, we offer a wide variety of specialty welding gas solutions to protect as well as fine-tune the material properties of parts printed with arc DED methods.
Quality gains with arc DED
Arc direct energy deposition (arc DED) is a new process that adapts time-proven arc welding and plasma arc welding tools and wire to the specific requirements of additive manufacturing (AM). Metal inert gas (MIG), metal active gas (MAG) and plasma welding techniques are used to melt metal filler to form a 3D component layer by layer. This process is also referred to as wire arc additive manufacturing (WAAM).
Arc DED 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/plasma AM processes
The advantages of laser and arc/plasma AM are clear, and the results are impressive. Plus, 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 DED interesting for many industries, in particular for aerospace, automotive and medical. It is also more cost-effective than other additive manufacturing processes like laser beam welding and electron beam welding.
Importance of shielding gases for arc DED
Air, hydrocarbons and moisture will lead to distortion. To avoid the chemical reaction experienced by heated metal when it comes into 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 for improved mechanical properties
Argon, helium and mixtures of these gases 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 our long-standing expertise in all welding, cutting, heating and surfacing applications, we 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 CORGON®, CRONIGON® and VARIGON® families. 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.
Additional cooling gas enhances grain structure and size according to latest research
In cooperation with a research team from the Department of Production Technology at Ilmenau University of Technology in Germany, a novel additive manufacturing gas cooling strategy was tested to avoid high heat accumulation in the top layers of the workpiece. Experimental trials with argon, hydrogen and nitrogen were carried out, proving the significant influence of cooling gas on the temperature during the gas metal arc welding (GMAW) additive manufacturing build process. The best results were achieved with nitrogen and hydrogen, which led to a highly effective cooling process. Hence, grain structure and size can be modeled to a homogenous microstructure with the right gas composition.
Build on our technical knowledge and industry experience
As the deposition conditions such as temperature and protective atmosphere are key determinants for the layer quality, our application experts can also advise you on the choice of shielding gas, a desirable shielding gas flow and other operating parameters best suited to your needs. We can also provide the equipment and gas management services you need. We would be glad to help you optimize all your gas-related procedures. In addition, we offer safety training and preventive maintenance.
Please contact us for personal consulting about our high-quality gases for additive manufacturing:
Linde solutions for arc DED processes at a glance
- Argon and helium gas supply – design, provision and installation
- Active gas supply – gases mixed in advance or on site to meet 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