On April 14, 2022, Antarctic Bear learned that the Swedish multinational engineering company Sandvik announced the development of a new type of 3D printable cemented carbide. Previously manufactured only by other technologies, this material has a unique cobalt and tungsten carbide matrix tough structure that gives it the durability needed to produce demanding, high-performance parts.
Sandvik said they prepared this new cemented carbide powder through an in-house developed process that could 3D print it into objects more quickly, "extending its service life by a factor of 20" compared to objects produced in other steel or alloys.
Anders Ohlsson, Chief Product Manager of Sandvik Additive Manufacturing, explains: "Our powders are optimized to print beautiful- and well-working parts and are suitable for use in practical applications, harsh environments and mass production. It is worth mentioning that the ability to 3D print cemented carbide has also greatly accelerated our time to market. Prototyping used to take 6-12 months, but now our lead times are only a few weeks, thanks to Sandvik's unique powder and process. ”
Sandvik's portfolio of 3D printing
While Sandvik's business covers the metal cutting, digital manufacturing, mining and construction industries, its 3D printing business generally focuses on powder development, as well as consulting and manufacturing services.
In terms of materials, Sandvik spent more than 15 years building an extensive portfolio of Osprey 3D printed alloys. These powders are produced via gas atomization towers and can be customized to any printing technology, with particle sizes ranging from 5 microns to 500 microns. The company's Osprey metal range ranges in batches ranging from 1 to 6,000 kg and now ranges from steel to nickel-based superalloys, enabling it to meet a wide range of applications.
Recently, these materials were applied in GE Additive's Binder Jet Beta Partner Program. Under a strategic partnership reached at the end of 2020, Sandvik used its Osprey powder to provide a testing mechanism for GE Additive's H2 Binder Jet 3D printer in exchange for the production rights to use the machine.
Since acquiring a stake in BEAMIT a year ago, Sandvik has also tried to push the limits of its additive manufacturing capabilities. Sandvik, for example, in partnership with its parts subsidiary, has now developed the ability to 3D print super duplex stainless steel parts, and recently began experimenting with 3D printing at boliden's mine as a means of improving the performance of drill parts.
Using its previously developed super duplex steel, Sandvik 3D printed an optimized offshore impeller (pictured). Image from Sandvik.
A new cemented carbide
Due to its unique composite structure, the wear-resistant phase is bonded together by a tough metal binder, cemented carbide gives it the strength needed to produce parts for metal cutting, agricultural, food and oil and gas applications.
Nevertheless, due to its inherent hardness, cemented carbide can be challenging when machining, especially into parts with complex geometries. Sandvik has been working with this type of material since 1932, trying to use its expertise to develop a new powder with "excellent wear resistance" to overcome this problem.
The powder was developed through an undisclosed "patented process" that is said to produce the same superhard parts as before, while also taking advantage of the reduced waste and increased design freedom that 3D printing brings.
Ohlsson adds: "When implementing additive manufacturing in your business, you basically eliminate all of the previous design limitations, allowing you to focus on designing parts according to operational needs and requirements, rather than having to adapt to a specific shape or form. Cemented carbide is one of the very hard materials, and our work has extraordinary significance in the field of 3D printing hard materials.
△ Parts 3D printed with cemented carbide. Image from Sandvik.
To demonstrate the potential application of this new powder, Sandvik 3D printed it into a brushed nib as part of a recent research and development project. According to the company, the component has a closed-loop spiral coolant channel that allows it to achieve efficient cooling while keeping the wire dry, something that traditional manufacturing methods cannot achieve.
Going forward, Sandvik believes the extreme durability of this material will make it ideal for industries with production efficiency optimization needs, especially those working in challenging environments.
Dr. Mikael Schuisky, Manager of Sandvik's Additive Manufacturing Division, concludes: "Thanks to our long experience in materials technology, coupled with our expertise in the additive value chain, we can innovate at a very short pace. This gives us a unique advantage in driving the shift in the industrialization of 3D printing and proves that sustainable manufacturing is not only possible, but already happening. For us, 3D printing of cemented carbide is the natural next step, compared to the materials we have perfected for decades. "
△ Sandvik's 3D printed tungsten carbide brushed nib. Image from Sandvik
Advances in high-strength materials
While Sandvik's cemented carbide breakthrough is undoubtedly impressive, it is far from the first to begin researching the material's 3D printing potential. In fact, back in 2019, VBN Components' tungsten carbide Vibenite 480 material won MM Maschinenmarkt's Additive Manufacturing Innovation Award.
Elsewhere, a number of other "superalloys" have also been developed, especially the additive manufacturing of high-strength components. Earlier last year, researchers at the University of California, Santa Barbara and Oak Ridge National Laboratory revealed that they had designed a new defect-resistant 3D printed superalloy capable of overcoming the cracking problems that often occur in components produced by high-temperature PBF.
Similarly, Rosswag Engineering has identified its nickel-based WASPaloy alloy some time ago, which is said to have good corrosion resistance and oxidation resistance. In the company's initial tests, Waspaloy showed tensile strength and 21 percent elongation at break at 1403 MPa, giving it superior performance over metals such as Inconel 718, which are typically used in demanding fields such as aerospace.