René Raaijmakers
9 November

Hittech and Norsk Titanium are set to use 3D techniques and post-processing to produce carrier structures for ASML. The savings on energy, time and material are substantial. Investments in CNC machines can be significantly reduced.

Mike Canario, CEO of Norsk Titanium, is in the best, almost exuberant mood. The American is visiting Hittech Bihca in Winterswijk. He and his Dutch hosts have just received the green light from Veldhoven: Hittech and Norsk are allowed to produce ASML’s carrier structures with 3D technology.

Each wafer scanner contains two of these complex manufacturing pieces. At Hittech Bihca, they still mill them from a block of 220 kilos of solid titanium. With a combination of 3D metal printing at Norsk and finishing at Hittech, the material consumption will soon be less than half.

Hittech Norsk 4566
Mike Canario, CEO of Norsk Titanium (second from the right), gets a tour of the Hittech Bihca factory, where carrier structures for ASML are milled. Credit: Tanja Bouwhuis BFD

The partners will start with carriers for lower-node machines. In the long run, the technology is expected to also be introduced for high-end scanners. In any case, the order is substantial and the publicly traded Norsk Titanium is going to issue a press release about it. Canario will also include it in the agenda for reporting quarterly results at the end of October. There, he’ll announce that production will commence this year.

With the order, Norsk is tapping into a whole new market. Its founders have been working on 3D titanium technology since 2007. Five years ago, things really picked up. In 2017, the company produced the first FAA-qualified parts for the Boeing 787 Dreamliner. In every 787, there are now structures from Norsk. The material is completely similar to alloyed titanium and has superior performance properties to castings. Airbus and aerospace companies have also started working with the Norwegian specialist. With his years of experience in composite materials for aerospace, Canario was brought in four years ago to turn all those opportunities into rock-hard business.

With Boeing as the lead customer and aircraft construction as the most important market, it won’t be surprising that Norsk had to downsize during Covid. In 2020, nothing happened in commercial aviation. Norsk even closed its R&D location in Norway and its factories in Plattsburgh (New York) for three months that year. At the latter location, Norsk’s metallurgists are working on the industrialization of the 3D technique for titanium.

For Canario, a foothold in the semiconductor market is a boost. At the same time, aircraft construction is gaining momentum again. The CEO expects to be fully qualified for Airbus around the turn of the year.

Hittech Norsk 4583
Mike Canario, Nicholas Mayer, Marco Verloop and Koen Mentink next to a carrier structure. Credit: Tanja Bouwhuis BFD

Pomo

In 2015, Norsk settled in the US, after which it established the world’s largest 3D mass production facility in Plattsburgh in late 2019 with 125 million dollars in support from New York State. For that, with a turnover of 7.9 million (2018) and 0.4 million dollars (2019), you have to have a good story. There are now 32 production machines in the American factory.

Last year, Norsk raised an investment of 38 million dollars and was listed on the Oslo stock exchange. The revenue forecast for this and next year is 10 and 15 million dollars, respectively. Canario expects that the New York plant will generate sales of 300 million dollars a year at full capacity.

In 2014, Hittech crossed Norsk’s path. Since then, the partners have been working on refining the processes in which Norsk melts up the rough structures and Hittech completes them with high precision.

The carrier structure forms the basis for the positioning module – “pomo” in ASML jargon – on which the wafer lies. There are two in each wafer scanner to speed up throughput. While one pomo has the wafers measured, the other zigzags under the lens for exposure, all with high speed and extreme precision. As this requires a frame with low weight and high stiffness, titanium was chosen.

Hittech has been making carrier structures for ASML since 2008. At that time, the pomo base consisted largely of composite materials with carbon fibers. As the number of boreholes and attachment points increased, the designers in Veldhoven opted for a switch to titanium. ASML selected Hittech as one of the companies to manufacture the carrier structures.

Infancy

With carrier structures, the trick is to take away as much material as possible. Because of high accelerations, the moving parts should be as light as possible. All this while maintaining the desired stiffness.

In the case of solid titanium, this is no small feat. The metal is relatively difficult to machine, the tools wear out quickly and the processing times are long. Hittech started using expensive machines to mill out huge blocks, followed by a post-processing step. With this approach, most of the titanium ends up as shavings in bulky recycling bins – less than 10 percent of the 220-kilo blocks is used. Titanium milling is a critical technology but also a necessary evil.

Today, Hittech is a bit of an outsider when it comes to metallurgy. The company has its roots in the steel and aluminum R&D of Hoogovens (now Tata Steel) and has experience with processes such as casting. Unsurprisingly, its engineers started thinking about pre-forms, ie parts that are pre-formed to minimize wasteful operations.

A casting process for titanium was investigated, but that option was quickly dismissed. “It turned out to be more expensive than the end product we delivered,” says Koen Mentink, branch director at Hittech Bihca in Winterswijk, one of the two locations where Hittech manufactures carriers. “The price didn’t come close to what we needed.”

Hittech Norsk workpiece
3D-titanium-printed experimental workpiece. Credit: Norsk

3D metal printing was also examined. Hittech gained initial experience with this in 2012. “We looked for suppliers all over the world because 3D printing seemed ideal to us,” says Marco Verloop, COO of Hittech Group. “But many of these techniques were still in their infancy. The process turned out not to be mature enough for production.”

Powder bed printers with a volume of 600 by 600 by 80 millimeters were not yet available, so evaluation was limited to models and calculations. “Based on knowledge about smaller powder bed printers, we calculated what we could expect in the future, but because of the low speed, we ended up with a price that was far above our selling price,” says Mentink.

Sustainable

In 2014, Verloop looked all over the world for alternative pre-form technology. After extensive research, he ended up at Norsk. The Norwegian specialist turned out to be developing a 3D deposition technique for customers in the aerospace industry. “Their rapid plasma deposition technology emerged as the best by far,” says Verloop. Norsk had Boeing as lead customer at the time and was at an advanced stage to qualify its technology for the aviation industry.

For Norsk, Hittech also came at the right moment. Its traditional partner network was running into technical problems. Machining complex pre-forms turned out to be different than working with rectangular material. “However, we had extensive experience with casting and finishing castings,” says Verloop.

Hittech uses, among other things, scanning technology to make images of the clamped workpieces. It allows a CNC machine to approach a piece quickly and safely with its end mill. This is an example of how Hittech helps its partner with rapid plasma deposition (RPD) qualification of products in the aerospace industry.

Norsk’s 3D technique is similar to welding. The machine is fed a titanium wire of 1.6 millimeters and plasma torches melt the metal drop by drop, layer by layer, on a thin base plate. “It’s a very controlled metallurgical process that ensures that we end up with the same mechanical properties as the standard titanium we start with,” says Canario. The 3D product’s shape roughly approximates the final product. For the carrier structure, the base material goes from 220 kilos of solid titanium to 80 kilos.

According to Canario, the 3D structures he supplies are the same as the solid starting material in terms of cost and price. “While the material is similar, it weighs less than half and you have a much shorter CNC machine time,” the Norsk CEO points out. He says that energy consumption is also reduced by more than half, and CO2 emissions are 40 percent less. “You have a better lead time, it’s more efficient, cleaner and more sustainable.”

Norsk pre form
3D-printed pre-form and final aircraft part. Credit: Norsk

Change of mind

Their combined experiences were such that Hittech and Norsk proposed to ASML the application of RPD for the production of titanium carrier structures. After all, the benefits were considerable, such as less waste and lower investment in expensive CNC machines. Various material studies, carried out on behalf of ASML, showed that the RPD material is of high quality and very suitable for the production of the carriers.

Employees at Hittech Bihca initially reacted skeptically when their boss showed them the first workpieces from Norsk. “Because of the heat treatment, the metal had a brownish color,” says Mentink. “They didn’t like that.” But their mindset changed after the first milling. “An operator came to me and said that his machine made a very even sound during machining, which indicates that the material is very consistent in quality.” Mentink concludes that this is due to the nature of the process, during which the amount of heat is constant. “There’s no difference between the inside and the outside.”

A second operator complimented his boss on the beautiful material. Mentink asked him why he had suddenly changed his mind. “He replied that he has to remove a lot less chips. They expand like foam. If we mill a 600 by 600 by 80 mm carrier, we have a cubic meter of titanium shavings. With an RPD workpiece, the bin only fills up after three workpieces.”

Norsk employees
Employees looking at the 3D titanium printing process with eye protection. Credit: Norsk

Perfect timing

At the beginning of 2015, the Dutch and Norwegians signed an official collaboration agreement and in the same year, the first titanium part was delivered. “Although smaller than the carrier, it had the same characteristics,” says Verloop. In the end, the partnership wasn’t authorized to start.

“However, we strongly believed in our technology and decided to further develop the printing technology together on our own,” says Verloop. In 2021, they manufactured the entire carrier structure for an NXT machine. The pre-form was printed at Norsk in Plattsburgh and finished by Bihca in Winterswijk.

The timing was perfect because almost simultaneously, ASML asked Hittech to think about cost savings. Verloop: “ASML told us that they wanted to make the carrier lighter. Their question was whether we could take away more material at the same price.” Mentink: “We reminded them of our 2015 proposal to use RPD.” Verloop adds, “It’s difficult to change anything in existing machine lines, but now, a new platform was needed with a lower bill of materials and that was our chance. We could immediately say: we have a carrier that’s ready to be tested by you.”

Open up

In the coming months, Hittech and Norsk will switch to full production. Mike Canario expects his relationship with the Dutch to develop further. “Hittech is one of our most advanced machining partners, even superior to many suppliers we work with daily in aviation. So, I expect that there will be interest and opportunities to work even more closely together.”

To support his argument, Canario talks about how Hittech started working with the first RPD prints. “Normally, we spend a lot of time explaining to machine factories how to process our product. Hittech did all that by itself.” Verloop: “At the time, we had a program running to scan products, so they came at the right moment and we also helped to process parts for Boeing.”

Norsk factory floor
Three years ago, Norsk received 125 million dollars in support from New York State to build the world’s largest 3D mass production facility in Plattsburgh. Credit: Norsk

“It was important that we were completely transparent from the start,” says Verloop, talking about the collaboration. “We started with an NDA and a partnership agreement. Then we said: okay, now we open up everything and we also want to see what you do with 3D printing. You can only optimize for the entire chain if you trust each other. We put our engineers together and said: let’s put everything on the table.”

Canario says that Hittech’s input actually helped Norsk improve its processes. “It enabled us to take a step toward higher reproducibility. That has also made our lives easier in aerospace.”