How WAAM could reduce supply chain blockages

For the sceptical: WAAM is not a new-fangled, unproven technology straight out of a research laboratory. First patented in 1920(!), WAAM is, in many industrial sectors, a tried-and-trusted additive manufacturing (AM) process. For at its core, WAAM is nothing more or less than a form of arc welding, a process that the global metal-working industry will feel completely at home with.

WAAM’s recent emergence as a viable engineering tool is due to two factors: firstly the development of CAD/CAM software, and secondly the introduction of advanced robotic systems. Hence WAAM systems available today can produce metal components in near net shapes, offering significant reductions in cost and lead times, material efficiency, and local, on-demand manufacture. Research-driven companies like MX3D in The Netherlands are championing the introduction of WAAM across a multitude of sectors. Recent company highlights include a 12 metre stainless steel bridge installed over a canal in Amsterdam, the delivery of a DED (Directed Energy Deposition) machine to German car builder BMW, as well as research work into the 3D printing of carbon steel piping components with Japanese engineering firm JGC.

And now MX3D has set its sights very firmly on the energy sector, says CEO Mr Van der Velden. “We are strongly focused on manufacturing equipment in specialty materials as well as special use, low-volume items. These are situations when WAAM can deliver serious benefits. For example, our technology gives customers the ability to rapidly produce parts in materials such as duplex stainless steel and high-end alloys that are difficult to source in castings.”

Another ideal application is emergency manufacturing, he continues. “We have identified that lead time reduction is key in areas like the valve industry. So while the impression may be that in a global marketplace you can source anything, anywhere, anytime, the reality is that valves manufactured in materials other than carbon steel are going to have lead times of several weeks or even months. By contrast, our system enables valve bodies, pump impellors, unique piping components and the like to be printed immediately.”

Industry feedback

To better understand the specifics of the flow control industry, MX3D sent a delegation to the recent Valve World Expo & Conference held in Dusseldorf. Discussions there confirmed Mr Van der Velden’s belief that WAAM could be a tremendous asset to valve manufacturers and users.

“People we spoke to were excited to learn how with a WAAM system it is possible to start printing on demand and to have a 100 kg valve body ready in just a few days. Of course, the valve body would need internal and perhaps external machining to create the required surface finish but that step is no different to the conventional manufacturing required for cast items.” Further, Mr Van der Velden notes a positive response when discussing the economic benefits of using WAAM.

“A common approach when making emergency items using specialty materials like duplex stainless steel is to machine down bar stock. However, during the necessary milling process, up to 80% of what is a very expensive material will be turned into scrap! At a cost of EUR 30 per kilo, you are literally throwing money away. WAAM is a much more economical option thanks to the near net shape results. Moreover, WAAM also scores from the sustainability perspective thanks to reductions in energy consumption and emissions.” However, Mr Van der Velden also understands the need to change a prevailing mind-set. “An interesting take-away from our visit to Valve World was the realisation that the valve industry is completely adapted to accepting such long lead times; this has been their normality for so long that it no longer seems unusual to wait six months for a valve. It’s a very disruptive idea that you can order a valve and receive it in a couple of weeks. We therefore plan to continue discussions at all levels, helping valve users to understand that WAAM is a viable, proven technology enabling the fast-track delivery of valves.”

Target audience

In theory, WAAM could be of interest to a huge number of industries. Asked about high potentials, Mr Van der Velden replies as follows: “We see significant interest from companies providing speciality items that are not made in large quantities; these are a target. Hence we have had promising discussions with quite a few companies active in the emerging hydrogen sector who want to scale up valve production in specific materials that are most suited to very low and cryogenic temperatures.”

The drive to reduce stock levels is also favourable for WAAM, continues Mr Van der Velden. “Nowadays many companies only stock standard items and certainly not expensive speciality equipment such as impellors which can cost upwards of EUR 100,000. Order one now and it will take weeks to arrive via conventional production, yet with one of our systems installed in a 3×3 metre corner of your facility you can print that self-same impellor on demand.” Interest in WAAM from general industries making commodity products is naturally lower due to the higher stock levels and simplicity of production. “Nevertheless, wherever buyers have lead time issues, you can rest assured that WAAM is a good solution,” comments Mr Van der Velden.

Shifting production

Interestingly, Mr Van der Velden indicates that it is not just the manufacturers who are interested in WAAM systems. “We have received plenty of interest in our technology and software from the big oil and gas companies. For them, lead times are everything. Hence in some circumstances, they want to be more independent from their traditional OEMs.”

As Mr Van der Velden explains, end user companies who purchase engineered equipment have the right to source spare parts elsewhere if, in the event of an emergency, the OEM is unable to supply the necessary components within a reasonable timeframe. Alternatively, the end user could manufacture those parts themselves, using WAAM to produce parts on demand. “Having an own WAAM system gives companies a more independent position. This is going to shuffle the way the supply chains work.”

Investing in WAAM is also a good option for end users who hold own the Intellectual Property Rights to specific items of equipment. “Traditionally, the end users would rely on getting products from the original manufacturer. Our technology means they can flip that around, engaging a more local manufacturer or perhaps even manufacturing themselves. Being more independent means you can shorten lead times and drive down costs. We have seen this step-change in the US Navy and Army; they have a think tank charged with creating ideas to reduce dependency on their suppliers, preventing delays and ensuring that parts can be remanufactured.”

Standards

An oft-raised question when discussing WAAM is whether sufficient standards are available. This is a topic Mr Van der Velden is keen to address. “There are already general standards such as API-20S (Additively Manufactured Metallic Components for Use in the Petroleum and Natural Gas Industries) and DNV-BT-203 (Addition Manufacturing of Metallic Parts) that allow end users to utilise metal AM in their production. There is also a more specific standard ASME Section IX (a segment of the ASME Boiler & Pressure Vessel Code that comprises regulations governing the qualification of welding procedures and welders), that allows 3D printing in our special way. Our method is Wire Arc Direct Energy Deposition (DED) and that has been covered for 18 months now. It’s a good sign that our process is standardisable; it also shows that there is a lot more coming.” Mr Van der Velden continues: “What we are doing is welding, which has been standardised for decades. We therefore started out by reviewing standards for welded parts. 3D printing is really nothing more than stacking welds on top of each other. Hence the original standards have been readily adapted to allow the 3D printing of entire objects. Of course extensive testing has been performed which demonstrates that the pressure retaining capability of these items is excellent. The material properties are also at a high level and often superior to those of cast items. We have therefore already hit all the benchmarks, delivering consistent material and reliable properties.”

Surface texture

When viewed up close, the surfaces of a WAAM printed item may appear ridged, causing raised eyebrows amongst people used to seeing smooth, shiny products. Such ridges are natural phenomenon caused by the welding process, states Mr Van der Velden. “The surface quality of a WAAM item is equivalent to that of a casting. If required, simply milling away between 0.5 – 1.5 mm creates a completely smooth surface. However this is only necessary when there are concerns about fatigue, inclusions or corrosion attachment, which can be the case if there is a lot of pollution. And even then it may not be necessary to mill the whole surface area.”

Mr Van der Velden adds that smoother surfaces can be produced by AM, but process selection is always a compromise. “Research clearly shows that our WAAM technology is the most cost-effective and fastest approach. Items made using Laser DED will be somewhat smoother but the process will take ten times longer. We can print between 5-9 kg per hour. Hence a 500 kg part can be produced in just 1.5 weeks. That explains the appeal to clients concerned about lead times. Their overriding goal is to obtain a fit for purpose solution with timely delivery.”

Start the conversation!

Although some of MX3D’s projects have made headlines in the mainstream media, the company is essentially a technology provider. Hence the company designs, engineers and fabricates complete WAAM systems which, thanks to proprietary software plus quality hardware such as robotic systems from renowned manufacturers, are fully geared to use in industry.

In addition, MX3D continues to produce parts at its own facility, be they print-on-demand components made for customers or prototypes for own research. Mr Van der Velden: “Software development is a key strength and running in-house production is an ideal route to fuel ongoing improvements. That’s why we have fitted our machines with multiple sensors so we can follow everything we do.”

Thanks to systems that automatically flag if maintenance or operator intervention are required, Mr Van der Velden is convinced that WAAM is a safer process than casting. “We control everything on the sub-millimetre level and generate data to support whether the quality is good or not. As a company, our challenge now is to identify the right business cases. That’s why we make new, unusual prototypes every year to trigger people’s imagination. Ideally they will say: ‘that’s great, but I have a completely different idea and material and want you to help me’.”

Mr Van der Velden is therefore never happier than when confronted with industry pain points. “If people explain their problems, we can adapt a machine to solve them. Sometimes customers indicate that a spotless finish is the priority so we can develop a slower program. Other customers indicate that speed is essential. So whatever their concerns, I encourage buyers and users of valves, pumps, vessels, etc, to contact us. Let’s start a conversation!”