Manufacturing ceramics can be quite challenging, especially to develop prototypes ahead of large-scale production. Breakthroughs in the field of additive manufacturing are on the verge of reinventing the manufacture of ceramics. The additive manufacturing of alumina is one of those breakthroughs.
Alumina 3D printing
What is Alumina
Aluminum oxide or alumina is an oxide ceramic, usually found as a white powder. It is the most used and cheapest high-performance ceramic.
Once shaped and sintered, these technical ceramics offer high performances for many applications in various fields such as aerospace and aeronautics, electronics, defense, or chemical industry among many others.
Alumina is well known for its hardness, it has a Vickers hardness of 2000HV, twelve times the hardness of 316L stainless steel.
This very hard material also presents excellent resistance to high temperatures with a melting point at 2072°C and can be used with temperatures up to 1500°C, its low thermal conductivity and thermal expansion coefficient makes it perfect for thermal insulation applications and a very good refractory material.
Alumina is also an excellent electric insulator and is widely used in electronics. It can be used not only for industrial applications but also in medical engineering for permanent implants or devices, due to its high biocompatibility.
3D printing with alumina
For additive manufacturing of ceramics, there are currently seven process families: material extrusion, material jetting, powder binder jetting, sheet lamination, stereolithography, powder bed fusion, and direct energy deposition. The most common process available on the market is the vat photopolymerization process of the stereolithography family.
This process works by curing a photosensitive slurry, a suspension of alumina powder, and organic additives, by exposing it to UV light in the shape of the layer cross-section of the object.
After designing the part on CAD software, it is necessary to prepare the model for printing, this step is called slicing. During the slicing, the model is cut into layers of the cross-section, all identical in thickness.
An STL (Standard Triangle Language) file is generated which can be read by the printer. Then, the alumina powder is mixed into a photosensitive resin to obtain a slurry which is loaded into the printer. Once the file is loaded, the printing process can start. Each layer of the part is constructed by projecting a UV light in the shape of the layer, the layers are constructed on top of another.
At the end of the printing process, the part obtained is called a “green”. The green part contains alumina but also organic and other additives. The green part is not fully dense yet, since it’s only about 60% of the maximum theoretical density.
The green part undergoes a first heat treatment called debinding. During the debinding, all additives are burned and only an alumina part remains.
Finally, a second heat treatment called sintering, allows densifying of the part. High density can be reached, up to 99% of the theoretical density of alumina. The part is ready to be used for its application.
If you are looking for an alumina 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.