Located in Sandviken, Sweden, close to Sandvik’s Additive Manufacturing Center, the Sandvik atomization plant produces the Osprey titanium metal powders. The very heart of the 200 MSEK (€20 million) plant, as well as the cradle of our production, is the atomization tower that rises more than nine meters tall, and safely encloses the process of EIGA – short for electrode inert gas atomization.
A vertically oriented, rotating titanium electrode is melted at one end, through a conical induction coil. The design of the coil is optimized to achieve just the right temperature to cause the melt to drop or – when skillfully controlled – continuously stream from the electrode end. As the metal runs through a slit below it is transformed by a high-velocity stream of argon, causing the melt to atomize. The outcome is millions and millions of micro-droplets that cascade down the tower and, as they fall, solidify to forms fine powder grains of spherical perfection that are ultimately collected in an airtight container.
The EIGA process
Once atomized the titanium is processed in the sieving tower, where a double-decker sieve separates powder grains according to their size. This is done to ensure our deliveries turn out top-of-the-line in terms of quality as well as homogeneity. Premium consistency is one of the most appreciated areas of differentiation when it comes to high-end metal powders used in AM, such as the Osprey brand of metal powders. After being thoroughly blended, a robot packs and seals the titanium powder which is then ready to embark on its journey to 3D printers all over the world.
The electrode melting Electrode Inert Gas Atomization technology (EIGA) system atomizes high-quality titanium powder with low oxygen and nitrogen levels. It is completed by a dedicated downstream sieving tower, large scale blending and packing facility. The highly automated plant also includes a sieving tower for nickel-based superalloys, ensuring even better reliability and consistency.
For Sandvik, having the full supply chain in-house – from titanium sponge to finished powder – ensures full traceability for the production of titanium powders for additive manufacturing, including Osprey Ti-6Al-4V Grade 5 and Grade 23, as well as Osprey Alloy 625 and Alloy 718. Other alloys are available on request.
While atomization is an energy-intensive process, powder manufacturing at Sandvik plant is based on 100% renewable energy, with all melting and heating is done by electric powered furnaces. All internal transportation is carried out by electrical vehicles. In addition, the heat recovery system in the building reduces energy consumption by 50 – 60% and all cooling systems are closed loops.
Alloying elements and scrap for the production are sourced from Sandvik’s steel mills in Sandviken and Hallstahammar, Sweden. Waste material from the process is re-melted either in either Sandvik’s own process or in the company’s 75 tonnes steel mill.