Manufacturing ceramics can be quite challenging, especially to develop prototypes ahead of large-scale production. Breakthroughs in the field of additive manufacturing (AM) are on the verge of reinventing the manufacture of ceramics. An increasing number of studies are being conducted to understand the formation mechanism of zirconia manufactured by AM processes and to improve the performances of those parts.
Zirconia dental 3d printing
What is zirconia?
Zirconium oxide ZrO2 or zirconia is an oxide ceramic, usually found as a white powder. It is a high-performance ceramic with many applications.
Zirconia has the particularity to present a monoclinic crystal structure at room temperature and tetragonal and cubic at a higher temperature.
Once shaped and sintered, this hard technical ceramic offers high performances for many applications in various fields such as dentistry, refractories, electrical insulation, abrasive tools, or automotive due to its excellent mechanical properties both at room temperature and high temperature.
Zirconia can be combined with other materials and elements. Alumina toughened zirconia (ATZ) is one of those materials where a small fraction of alumina is added to zirconia to improve significantly its mechanical properties.
Yttria-stabilized zirconia (YSZ) is another common material that has a different microstructure made to improve electrical conductivity at high temperatures for application as a solid-state electrolyte for a fuel cell.
Zirconia is a hard ceramic, it has a Vickers hardness of 1250HV. It demonstrates excellent mechanical properties and it is a ceramic that has the highest fracture resistance.
The biocompatibility of zirconia added to its mechanical properties makes it perfectly suitable for medical applications such as dentistry where no other known materials can resist such an environment as the human mouth.
Zirconia also presents excellent resistance to high temperatures with a melting point at 2715°C and can be used with temperatures up to 1200°C.
At room temperature, zirconia is an electric insulator, heat it above 1000°C and it becomes an excellent ionic conductor. Yttria-stabilized zirconia (YSZ) is the most common solid electrolyte for Solid Oxide Fuel Cell (SOFC).
3D printing with zirconia
The AM techniques used to manufacture zirconia materials are selective laser sintering (SLS), selective laser melting (SLM), stereolithography (SLA), and ink-jet printing (IJP), but the most common process available on the market is Digital light processing (DLP).
For DLP, a mirror is used to directly project the image into the whole area to realize surface curing. As such, the scanning can be cured in a single layer, which greatly improves the printing rate, and the accuracy mainly depends on the resolution of the mirror device.
This process was developed for the production of complex technical ceramics that requires high accuracy. The part is printed in a bottom-up configuration which only requires a small amount of slurry compared to another configuration.
To obtain high density after sintering, once printed, the part undergoes a heat treatment to remove the additive and densify the part. The heat treatment cycle is optimized to avoid the formation of defects and micro-cracks, close porosity, and consolidate the grains.
It has been demonstrated in the literature that flexural strength close to conventionally produced zirconia can be achieved with the DLP process and adapted slurry. Density over 99% of the theoretical density of zirconia can be achieved.
If you are looking for a zirconia 3D printing service, you have come to the right place.
You can upload your file to Beamler’s platform and our team will provide you with a quote as soon as possible. Don’t worry, all uploads are secure.