According to the market understanding of 3D Science Valley, Sandvik recently announced that it will continue to expand its additive manufacturing products by introducing 3D printing cemented carbide with excellent wear resistance. With 160 years of leading materials expertise and the broadest range of metal powders on the market, Sandvik has been innovating in cemented carbide since 1932. Today, Sandvik is a world leader in cemented carbide materials such as metal cutting and mining tools such as turning inserts, end mills and drills. Now, Sandvik is expanding its product range to also include 3D printed carbide components.
Cemented carbide has unique properties due to its composite structure, consisting of a wear-resistant phase held together by a ductile binder metal, and is used in a variety of industries including metal cutting, agriculture, food and oil and gas. Due to its inherent hardness, cemented carbide is difficult to machine, especially in complex geometries.
Leveraging its century-long materials expertise, Sandvik can now offer commercial-scale 3D printed carbide based on custom powders obtained through a proprietary process – with design freedom, less material waste and fewer additives Manufacturing Technology.
Sandvik's cemented carbide powders are optimized to 3D print components that look great, work well, and are suitable for use in real-world applications, harsh environments and series production.
The most critical part of the 3D printing carbide process is using powders with just the right properties. Above all, high density has a crucial influence on the achievable quality in terms of material properties and geometry. Sandvik has developed unique powders and processes. 3D Science Valley learned that Sandvik powders are optimized to print components that look good, work well, and are suitable for use in real-world applications, harsh environments and mass production. Notably, the ability to 3D print cemented carbide greatly speeds up product development and commercialization times. Prototyping used to take 6 to 12 months, now the lead time from development to commercialization is a matter of weeks.
Carbide is by far one of the hardest materials for 3D printing shapes, and through additive manufacturing, virtually all previous design constraints have been removed – allowing product developers to focus on designing components according to operational needs and requirements , without fitting a specific shape.
A key difference compared to other hard materials is that these alloys are often brittle to some extent, and 3D Science Valley understands that the matrix structure of cemented carbide is mainly composed of cobalt and tungsten carbide, which has a unique toughness. Due to the extreme durability of the material, printed components are ideal for most industries looking to optimize productivity, including those operating in challenging environments:
Carbide is arguably the most successful and widely used material for cutting tools such as turning inserts, drills or saws for metal, concrete, wood and other materials.
Additive manufacturing brings a paradigm shift in flexibility in terms of quantity and design, and allows for the efficient production of single custom knives all the way to mass customization and production. New and innovative designs can include, for example, efficient cutting geometries, chipbreakers on any side and any shape, integrated cooling, increased number of cutting edges, and more.
Wear parts challenges exist in virtually every industry, and wear-resistant components greatly impact service intervals as well as uptime and productivity. Carbide is very wear resistant and can typically extend the life of a component by a factor of 3-20 compared to any steel or metal alloy.
Many have struggled with the design constraints imposed by traditional carbide manufacturing - preventing the full potential of these components from being realized. By implementing additive manufacturing, a range of products in virtually any complex geometry can be efficiently produced, enabling improved functionality across various industries. Of particular relevance to additive manufacturing are components with fluid channels, ports, and similar parts, since channels and other arbitrary cavities are difficult to drill, but are no problem to 3D print.
Nozzles are used in several industries and applications and are often subject to severe wear. Carbide has excellent wear resistance and can typically extend the life of components by a factor of 3-20 compared to any steel or metal alloy.
Fabricating carbide nozzles has previously presented challenges, being expensive and limiting in terms of design optimization. Using 3D printing - Additive Manufacturing technology, the nozzles can be manufactured efficiently, with features such as curved channels, threads and other mounting solutions, and delivered just in time.
Traditional machining processes, usually by uniformly pressing tungsten carbide powder in flexible bags, are used to manufacture large-scale carbide workpieces or carbide workpieces with high aspect ratios (such as end mills and drill holders). Although the production cycle of the equalizing method is longer than that of the forming method, the manufacturing cost of the tool is lower, so this method is more suitable for small batch production.
Carbide workpieces can also be formed by extrusion or injection molding. The extrusion process is more suitable for the mass production of axisymmetrically shaped workpieces, while the injection molding process is usually used for the mass production of complex shaped workpieces. In both molding methods, grades of tungsten carbide powder are suspended in an organic binder, which gives the homogeneity of tungsten carbide mixtures such as toothpaste. The mixture is then extruded through an orifice or molded into a mold cavity. The characteristics of the tungsten carbide powder grade determine the optimal ratio of powder to binder in the mixture and have a significant impact on the flow of the mixture through the extrusion orifice or into the die cavity.
After the workpiece has been molded, pressed, extruded or injected, the organic binder needs to be removed from the workpiece before the final sintering stage. Sintering removes porosity in the workpiece, making it fully (or substantially) densified. During sintering, the metal bond in the press-formed workpiece becomes liquid, but the workpiece retains its shape through a combination of capillary forces and particle contact.
After sintering, the geometry of the workpiece remains unchanged, but its size shrinks. To achieve the desired workpiece dimensions after sintering, shrinkage needs to be considered when designing the tool. When designing the tungsten carbide powder grade used to make each tool, it must be ensured that it has the correct shrinkage when pressed under the proper pressure.
People in the industry who are familiar with Binder Jetting 3D printing technology can easily find that the degreasing and sintering process of cemented carbide workpieces manufactured by traditional injection molding process and the post-processing process required by Binder Jetting 3D printing technology is consistent.
