Austrian company voestalpine has been engaged in 3D printing with metals for many years, mainly as a provider of metal 3D printing services and metal powder materials for PBF and DED technologies. These metals are already being used at its own 3D printing and research centers around the world. Now the steel and technology Group has started operating a giant sand 3D printer for heavy steel castings at its site in Traisen, Lower Austria. However, a unique and interesting aspect is that the machine is not from European and US leaders such as voxeljet and ExOne but from Chinese company Kocel Machinery.
In fact, voestalpine has been collaborating with Kocel since 2014, when the group expanded its special steel activities in the Chinese market, targeting the Chinese premium market with its €140 million EUR investment in Yinchuan (Ningxia province) and working together with local company Kocel to produce highest-quality tool steels and forged materials for the automotive, consumer goods, and mechanical engineering industries.
The new additive manufacturing technology for the production of sophisticated castings using silica sand that was installed in Austria reduces production times and is more environmentally friendly than previous processes.
Additive manufacturing has long since become an established production method, particularly in the aerospace, automotive, and toolmaking industries, as well as in the field of medical technologies.
Over the past years, voestalpine has consistently expanded its activities in the field of 3D printing with metals.
“The new 3D sand printer in Traisen represents a key technological advance for steel casting, and the company expects that it will hugely increase our competitiveness in this area,” said Herbert Eibensteiner, Chairman of the Management Board of voestalpine AG.
voestalpine Gießerei in Traisen, a subsidiary in the Steel Division of the voestalpine Group, has installed this first printer at its new 3D sand printing competence center; a second printer will follow in spring 2022. The 3D printer model is the Foundry Sand 3D Printer-AJS 2500A/2600A from Kocel Machinery, with EU CE and ISO 9001 certification; featuring a resin binder recovery system for low resin consumption is low and enabling the use of new sand, reused sand and reclaimed sand. The two models have build volumes of 2500×1500×1000 mm and 2600×2000×1000 mm respectively and measure 6 meters in length (and almost 6 meters in width), weighing 30 and 35 tons respectively. Printing at 0.2 mm layers, supported materials include quartz sand, and ceramsite sand, with furan resin, phenolic resin and inorganic resin binders.
“We are European pioneers in the use of 3D sand printing technology in steel casting, allowing us to offer our customers even more customized solutions of greater design complexity. This not only opens up new business areas for the future, but also creates new opportunities for our employees to work in an innovative environment at our established site in Traisen,” said Hubert Zajicek, Member of the Management Board of voestalpine AG, and Head of the Steel Division, based in Linz.
During the process, a 3D printer uses CAD data to directly produce sand molds into which liquid steel is poured. The sand molds are created by the repeated application of 300-micrometer-thick layers of chemically bonded silica sand. Large sand molds can also be printed in several separate sections and then combined. As a result, complicated wooden models are no longer required, so that molds can be manufactured more quickly and with more near net-shaped contours, particularly for complex castings. This significantly shortens or even eliminates final in-house processing, as well as steps such as welding and forging undertaken on the customer’s premises.
The innovative manufacturing process is primarily used to produce castings for the energy industry, and for the automotive and railway sector. One recent order, for example, was for rotor discs for water turbines. By removing the need for wooden models, integrated sand recycling, and simplified logistics, 3D sand printing is also more sustainable and environmentally friendly than the process it replaces.
Whether from traditional Western segment leaders or other machine providers, 3D printed sand casting seems to finally be catching on with many large companies. If properly implemented, the technology holds huge promise for both AM and adopting industries.