After enlarging the printing build volume of the Admaflex300, the Netherlands-based ceramics AM hardware manufacturer Admatec has introduced a new integrated debinding and sintering furnace, with an enlarged inner volume, increasing the throughput and efficiency in technical ceramic 3D printing and post-processing.
Technical ceramics 3D printing is one of the most advanced segments in additive manufacturing and one of the hardest to implement. With regards to material properties, ceramics are often used when other materials fail, because of the limited hardness, corrosion resistance, or temperature resistance. To shape technical ceramics, there are several solutions, such as pressing, which has limited design freedom, or injection molding which requires the production of a mold. Technical ceramics 3D printing offers the ability to produce complex shapes directly from a CAD file, without the need of a mold, with material properties comparable to traditionally produced ceramics – when using the appropriate 3D printing technology, materials, and furnaces.
3D printed high-performance ceramic parts are used in many applications, such as aviation, aerospace, medical tools, R&D, catalysis, refractories, energy, chemical industry, electronics, semiconductors, CO2 capture, refractories, aesthetics, jewelry, optomechatronics, and many more. In addition to the full density ceramics, porous ceramics, such as bonelike materials for patient-specific medical implants and leachable ceramics to produce ceramic cores and shells for investment casting, are also available.
In order to have full density technical ceramic products with high strength and smooth surfaces, ceramic particles with very small grain sizes are needed, as these allow full densification during sintering. Very fine powders cannot be processed safely in a dry powder bed. A proven solution is to work with pastes or slurries. By using slurries that consist of high ceramic filled UV sensitive resins, 3D printing is possible with high resolutions (<40 um) and after post-processing in the debinding and sintering furnaces, high-quality parts are obtainable.
When printing ceramics, a printing system that can handle high viscosity slurries is needed. In 2013, Admatec developed a printing technology which combines tape casting (for slurry deposition) with Digital Light Processing (UV curing using stereolithography) to produce ceramic parts. Since the introduction of the Admaflex130 printer in 2016, many machines using this Admaflex technology have been delivered worldwide, to renowned ceramic producers, ceramic 3D printing contract manufacturers, universities, and governmental labs, that have proven the ability to shape and sinter high-quality parts with excellent material properties and narrow tolerances.
When the lithography-based ceramic additive manufacturing technologies and systems were introduced in 2013, typical projection areas were 96x54mm at a resolution of 50μm. The debinding and sintering was executed in two separate furnaces, resulting in a thermal process of almost 2 weeks. In response to the requests from the market for more efficient serial production, Admatec developed larger printing machines, currently enabling projection areas up to 260x220mm in one single machine. The DLP printing process which cures the next layer of a full build platform in a few seconds, in combination with tape casting to deposit a new slurry layer, increases the speed to up to 300 layers per hour. Materials have been optimized for faster debinding and higher final density and mechanical properties.
Since 2018, Admatec has offered a compact, integrated debinding and sintering furnace, specially designed for the post-processing of 3D printed technical ceramics. This furnace allows for safe, controlled debinding and accurate sintering with temperature uniformity. With a volume of 180x180x200mm and a maximum temperature of 1700°C, this furnace is a cost-effective and efficient solution to debind and sinter small parts printed in oxide ceramics. After enlarging the printing build volume of the Admaflex machines to 260x220x500mm, a logical step to upscale to mass production, Admatec introduced a new integrated debinding and sintering furnace, with an inner volume of 400x400x400mm.
All these improvements, in combination with specially designed integrated debinding and sintering furnaces, currently allow for the production of a set of 3D printed technical ceramic parts, from CAD design to sintered end-use parts, in less than 7 days. With a maximum temperature of 1700°C and a useful inner volume of 64 liters, the new furnace has almost 10 times the size of the compact integrated furnace, dramatically increasing the throughput and efficiency in technical ceramic 3D printing and post-processing.