Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of hardmetals are manufactured by uniaxial or cold isostatic dry pressing, extrusion and injection molding as well as by green shaping at Fraunhofer IKTS. In traditional tool manufacturing, complex geometries, such as helical or meandering cooling channels inside the component, are still implemented at high cost or not possible at all.
Design flexibility by additive manufacturing
"Meanwhile, it is known that through resource-saving and tool-free 3D printing even complex, individualized ceramic geometries can be realized quickly", says Dr. Tassilo Moritz, group leader "Shaping" at Fraunhofer IKTS.
Now IKTS scientists also succeeded in producing complex hardmetal tools via 3D printing processes. The binder jetting method is used in this case. The starting powders or granules are locally wetted with an organic binder by a print head and bound. The challenge was to get one hundred percent dense components, which have a perfect microstructure and thus good mechanical properties.
Hardmetals consist of a ceramic hard phase, such as tungsten carbide, and a metallic binder matrix of cobalt, nickel and/or iron.
By varying the metallic binder, bending strength, fracture toughness and hardness can be adjusted individually – the lower the amount of binder in the hardmetals, the harder the tool material. The prototypes manufactured at Fraunhofer IKTS have a binder content of twelve and seventeen percent by weight and show a structure comparable to conventional routes. "Through the use of 3D printed complex green bodies which were subsequently sintered under conventional sintering conditions, we achieved components with a typical hardmetal structure and one hundred percent density. Moreover, it is possible to get a homogeneous cobalt distribution, thus achieving a comparable quality to conventionally produced high-performance cemented carbide-based tools," explains Johannes Pötschke, group leader "Hardmetals and Cermets" at Fraunhofer IKTS.