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New gas mixture brings FDM 3D metal printing one step closer

Air Liquide has developed a new gas mixture that is used in the FDM production process based on metal extrusion. This requires the gas mixture to be very pure, especially in terms of the hydrogen content. Gas mixtures with such precision are considerably more difficult to produce than other types, which increases the price.

Fused Deposition Modeling (FDM) is a specific form of Additive Manufacturing that is suitable, among other things, for prototypes and small production quantities. FDM distinguishes itself from other techniques because the 3D printer does not have to be placed in an enclosed space, nor does it require special safety measures. Originally, FDM used thermoplastics as a raw material, but now more advanced forms of FDM based on metals and polymers are available on the market. The polymers are only needed for the production process, and do not appear in the final product.

Perfectly balanced

The FDM (Fused Deposition Modeling) production process based on metal extrusion consists of three steps. After the actual printing, the printed piece is immersed in an aqueous substance to dissolve the adhesive residues. Finally, the piece is heat-treated (sintering) to remove any imperfections that may have occurred during the printing process.

The sintering process requires a perfectly balanced gas mixture, consisting of hydrogen (to remove the oxygen) on the one hand and argon (to create an inert atmosphere) on the other. “The customer stated that the gas mixture had to be very pure, with the hydrogen content in particular remaining within strict limits”, explains Nadia Bakker, Offer deployer Benelux at Air Liquide. “Air Liquide can supply gas mixtures with that kind of precision, but these are considerably more expensive than gas mixtures requiring slightly less precision.”

The cost for such a precise gas mixture is approximately € 300 to € 400 per cylinder (50l). And since a company printing full-time via metal extrusion consumes two 50-litre gas cylinders a week, the cost of the mixture amounts to around € 700 a week. A significant amount, with a major impact on the total cost of production.

Faster delivery

“Because the gas mixture was developed in close consultation with printer manufacturers, end-users have the assurance that the new mixture does not breach warranty conditions. Moreover, as mentioned before, it is significantly cheaper, and it can also be delivered much faster than before’, explains Nadia Bakker.

The new mixture is already available for companies in the Benelux and in Scandinavia and will soon be offered in other countries.

“We are very satisfied because, through effort and knowhow, we’ve been able to offer our customers a better solution”, concludes Nadia Bakker. “And of course, we are happy to investigate whether we can also help to improve other Additive Manufacturing techniques or make them more cost-efficient. We’ve also developed a number of training courses for Additive Manufacturing companies on the safe use of gases. Often these companies have little experience with gases, and so training is of course a good thing”.

As a company, would you like to find out whether Air Liquide can help optimise your AM production process or are you interested in training? Please contact Nadia Bakker, Offer deployer Benelux at Air Liquide.