Holistic approach to additive manufacturing

Additive manufacturing (AM) components must withstand a high level of pressure. Pierre Foret, head of AM at Linde Group explains, why only a few companies worldwide have the capacity to control every step in the AM value chain from powder production to cleaning.

Gas is important for AM, from powder production through the build-up process to post-manufacturing processing – image courtesy of Linde

The quality of AM components depends on each and every step in the manufacturing chain, from powder production through the build-up process to post-manufacturing processing such as heating or cleaning.

But, as process gases are required for almost all the various applications across this value chain, only companies with the practical experience and technical expertise of how atmospheric gases react can provide valuable advice on each step.

The global industrial gases company, The Linde Group, headquartered in Munich, is engaged in an international network of industrial users, powder producers, equipment manufacturers and research institutes to develop and improve industrial AM solutions for the automotive, aerospace and medical industries, among others.

Pierre Forêt, head of the global development centre for additive manufacturing at Linde in Munich, spoke to The Manufacturer about the challenges surrounding additive manufacturing across industry sectors and explained how Linde avails of its own additive manufactured components.

How would you describe Linde’s approach towards additive manufacturing? 

Linde is interested in developing two approaches in relation to additive manufacturing.

On the one hand, we are a gases company – from the ground up – and Linde’s aim has always been to not only sell gas – argon, nitrogen, helium and so on – but to develop the technologies that really enable all the gases we provide to be as effective as possible. And that is what we are doing with additive manufacturing.

Everybody seems to have a 3D printer or is producing powders or doing post treatment, like heat treatment, where argon and nitrogen are needed. My role and the role of my team is to optimise how gases can enhance those technologies for our customers so they can improve the quality of their manufactured parts.

On the other hand, Linde uses the technology itself as we produce millions of component parts, not only within the gases division, but also at Linde Engineering, the other major part of the Linde Group.

From Linde’s viewpoint, which sector is seeing the most tangible benefits from embracing additive manufacturing? 

Linde Engineering is focused on big, complex construction projects such as refineries and chemicals plants – plus the building of our own air separation units – all over the world. So, millions of components are needed and Linde Engineering sees a huge benefit of using additive manufacturing.

The challenge is that the manufacturing processes require of a lot of high pressure components, and when you have several hundred bars of pressure, you need to be sure that the additive manufactured parts can withstand that pressure.

So, at the moment there is a lot of work being done to try to solve all the regulation issues, so additive manufacturing can be used for production of high pressure components.

For example, Linde Engineering is currently collaborating with a working group which improves the quality of pressure vessels in Germany. The working group is organised by the VDMA (translated to Mechanical Engineering Industry Association), a global organisation made up of more than 3,200 global companies across capital goods to share best practice in mechanical engineering.

Linde is working with the VDMA to define how AM-produced vessels should be tested and validated before wider use in customer applications.

For the manufacturing of those types of components, along with the required gas, we have a few pilot projects in progress – for example, using additive manufacturing to develop a faster burner for combustion processes in order to improve performance.

Can you give an example of how Linde makes use of AM? 

The development work is done is Munich as that’s where our global development centre for additive manufacturing is located. We have recently built two prototype burners for the glass industry through the additive manufacturing process.

One of these burners is for glass polishing and the other, called a flat flame burner, is for glass melting for example (but not only) when existing glass bottles are to be recycled. To melt glass you need a lot of energy, so more efficient burners are needed, which can be achieved through the additive manufacturing process.

This is just the tip of the iceberg. As we promote our additive manufacturing capabilities within Linde itself, we expect the news of our successes will gather momentum and we will get more and more enquiries from colleagues so we can help them take advantage of the technology.