The ceramic suspensions used with 3DCERAM machines are photosensitive suspensions. This means, by using stereolithography technology, they react to UV wavelengths. It is therefore essential to protect them from white light. To achieve this, the room in which the machine is located must be equipped with yellow lighting and, if there are windows, these must be blacked out with yellow or red film.

Controlling temperature, humidity and air quality ensures that the machine operates in optimum conditions. To achieve this, we recommend installing the C101 EASY LAB or FAB in a room that is :

- Clean and free of areas likely to generate dust,
- Air-conditioned,
- where humidity can be controlled.

3D printing, or additive manufacturing, offers many advantages in the field of ceramics:

- Personalization or customization: 3D printing makes it possible to create unique, complex parts that would either be impossible to produce using traditional methods, or would require several steps including, most of the time, human intervention. This would have the impact of increasing the amount of scrap on a production run.

- Speed: 3D printing considerably reduces prototyping time, and therefore time-to-market. We also need to consider production speed. Considerable progress is currently being made by 3D printer manufacturers to increase production capacities. However, not all technologies are equal when it comes to machine productivity. Top-down technologies benefit from the possibility of having larger printing surfaces, which, combined with optical chains featuring several lasers, ensure high-performance lasering times. At the mechanical level, too, times can be optimized, thanks in particular to artificial intelligence.

- The right amount of material: as opposed to subtractive manufacturing, additive manufacturing uses only the quantity needed, thus reducing waste. Any material that is not polymerized can be filtered for reuse.

- Design flexibility: Offers unprecedented design freedom, much appreciated by engineers and designers to optimize the functionality of printed parts. However, it's inaccurate to say that anything is possible with 3D printing, but it's certainly the shaping process that overcomes the most design challenges.

- On-demand production: The agility of additive manufacturing means that small production runs can be produced at no extra cost. This is also known as “mass customization”, as parts with different geometries can be produced in the same print run. Whatever the geometry of the parts to be printed. However, we're talking here about printing surfaces, which are often limited. What's more, mass customization is only conceivable on printers with large printing areas. See here C1000 FLEXMATIC and C3601 ULTIMATE.

- Cost reduction: The principle of production on demand is applicable to 3D printing. This reduces storage costs. In addition, there are a number of service bureaus around the world with several 3D printing technologies at their disposal. These service bureaus are therefore able to meet prototyping needs. Proximity reduces the logistical impact.

In the 3D printing process, producing the part is only the first step. Once the part has been printed, it must be cleaned to remove all the ceramic formulation. This is usually done in a fume hood, using a solvent.

Once cleaning is complete, it's time for debinding.

Debinding is an essential phase in the ceramic 3D printing process, taking place after printing and before final sintering of the part. Its purpose is to remove the organic binders used to give “cohesion” to the ceramic formulation during printing.

Debinding produces a “pure” ceramic part. This is an important step, as it prevents the formation of defects during final sintering, in order to give the desired properties to the final product.

Debinding involves slowly heating the printed part to 600° to allow the organic components to volatilize. This stage can last from a few hours to several days, depending on the printed part. There are several processes, and debinding can be carried out under air or nitrogen. This creates porosity in the structure of the printed part. Debinding is an important and delicate stage, requiring precise control to avoid deformation or cracking. This stage has a direct influence on the quality and performance of 3D-printed ceramic parts.

Once debinding has been completed, the final stage of the process is sintering. This phase takes place after debinding, and transforms the “porous” part into a dense, resistant ceramic part.

Sintering is therefore a heat treatment involving “firing” the part at high temperature, generally between 1300°C and 1700°C. This process consolidates and densifies the ceramic.

The objectives of sintering are to

- Densify the structure of the part,

- Improve mechanical properties,

- Increase strength and hardness.

Sintering process steps :

- Temperature rise: gradual, controlled heating

- Sintering stage: Holding at maximum temperature

- Cooling : Controlled temperature drop

Sintering parameters in ceramic 3D printing, such as maximum temperature, depend on the ceramic used. Sintering time depends on the part.

It's important to note that during the sintering process, it's the ceramic particles that bind together. They become denser as the grains grow, which eliminates all the porosity resulting from debinding. As a result, the final part shrinks, losing on average 20% of its volume.

Physical phenomena during sintering :

Sintering is a delicate stage that requires mastery if the desired properties of the 3D-printed ceramic part are to be achieved. This final phase largely determines the characteristics and quality of the finished product.

Yes, 3D-printed ceramics have the same properties as those made by conventional processes, provided the same powder and sintering cycle are used.
The stereolithography (SLA) technology used to 3D print ceramics has no impact on the material's intrinsic properties.
Characteristics such as :
- mechanical strength
- thermal conductivity
- chemical resistance

remain identical, guaranteeing the quality and performance of 3D-printed parts.
Since the formulations are produced on the same ceramic powder base, there is no impact, as only a resin binder is added to enable the laser action, which hardens the material to give it its shape.
The firing cycle then removes all the resin during the debinding cycle at 600°. Densification of the ceramic grains takes place in the final sintering cycle at 1300°, depending on the type of ceramic (alumina, zirconia, etc.). In fact, this stage depends on the type of ceramic concerned, whether it's oxide or non-oxide, and whether firings are carried out under air, argon or other conditions.

Stereolithography (SLA) offers several significant advantages over other ceramic 3D printing technologies:

- High density: parts printed by stereolithography have a density close to 100%, reducing porosity. The high density of parts produced by stereolithography (SLA) is one of the most significant advantages of this ceramic 3D printing technology. And it's one of the first questions asked.

What is density in ceramics? The density of a ceramic part is the ratio of its mass to its volume. A density close to 100% means that the part contains very few voids or pores, which is generally desirable for most ceramic applications.

The importance of high density :

High density means greater mechanical strength, increased hardness and improved toughness.

Dense ceramics also conduct heat better, which is crucial for certain thermal applications.

High density makes parts more impervious to liquids and gases.

The less porous ceramic parts are, the more resistant they are to corrosive agents.

Precise suspension formulation: the “slurry” used in SLA consists of fine ceramic particles dispersed in a photosensitive resin.

The layer-by-layer polymerization process ensures controlled, uniform polymerization, creating dense, homogeneous layers.

Post-treatment, the debinding and sintering process is carefully controlled to remove the resin and densify the ceramic structure.

Compared with other technologies, SLA achieves higher densities than other ceramic 3D printing methods such as FDM (Fused Deposition Modeling) or Binder Jetting.

This has an impact on applications. The high density achieved by SLA broadens the range of possible applications for 3D-printed ceramics, particularly in demanding sectors such as aerospace, medical or high-performance electronics.

Although SLA enables high densities to be achieved, precise control of printing and post-processing parameters remains crucial to maximize density while minimizing potential defects such as cracks or deformation.

Precision and tolerances

After density, SLA's greatest asset is the precision and detail the technology is capable of producing. Indeed, SLA enables fine detail and precise dimensional tolerances to be achieved.

Typical ALS resolution ranges from 25-100 microns, depending on the formulation used, enabling finer details to be produced thanks to the laser spot.

SLA is reputed to be slower, but the possibility of installing several laser heads reduces the time required.

Tolerances for extremely fine detail are tighter with SLA than with DLP, which is dependent on pixel size.

Finally, one of the major advantages of stereolithography is its ability to print large parts. In fact, SLA can be deployed on large printing plates while maintaining a high standard of precision over large surfaces.

Moreover, printing large, monolithic parts in a single piece avoids the need to assemble parts, which can create areas of fragility.

Stereolithography or SLA is an additive manufacturing technique, also known as 3D printing, which uses photopolymerization to create three-dimensional objects. Here are the main stages in its operation:

- 3D modeling: The process begins with the creation of a digital model using Computer-Aided Design (CAD) software. The model is then converted into a format compatible with the SLA printer, usually an STL file.

- Printer preparation : The 3D file is imported into the printer software, which cuts it into a series of 2D layers. The model is then positioned in the print volume, and the print parameters adjusted.

- Formulation tank: The SLA printer uses a tank filled with photosensitive formulation, a liquid material that hardens when exposed to an ultraviolet (UV) light source.

- Layer-by-layer printing: Printing begins with the first layer, which involves spreading the formulation over the entire printing plate. A UV laser beam is directed through a system of moving mirrors (galvanometers) to draw the cross-section of the object on the formulation, which solidifies only where the laser hits it, forming a thin layer of solid material.

- Platform movement: Once a layer has hardened, a scraper deposits and spreads a new layer of ceramic formulation. The laser then repeats the process to solidify the new layer. This process is repeated, layer by layer, until the entire object is formed.

Find out more about stereolithography.

These are formulations that come in liquid, low-viscosity form.

Unlike other technologies that use powder, filaments and pellets, stereolithography 3D printing requires slurries of around 5 Pa.s.

Several factors need to be taken into consideration when assessing SLA printing speed:

- Layer thickness: the thinner the layers, the longer the printing time.
- Laser speed and power have a direct impact on printing time.
- To achieve a balance that preserves print quality, all these parameters are tested and adjusted according to the formulation and print project, in order to optimize the process.
- Part geometry: complex parts with a lot of detail will logically take longer to print.
- However, it is possible to reduce printing time by making use of the available printing area, enabling a series of parts to be printed simultaneously.

Stereolithography 3D printing technology (SLA) is capable of processing and printing a wide variety of ceramic materials. In addition to traditional oxide-based ceramics, SLA can also print a range of advanced ceramics, including nitrides.

SLA-printable ceramic oxides include alumina (Al2O3), the most widely used in 3D printing for all applications. Zirconia (ZrO2) and silica (SiO2) are also frequently used. These materials, with their unique properties such as high hardness, excellent wear and corrosion resistance, and good thermal stability, offer a wide range of applications in cutting-edge sectors such as aerospace, electronics and medical devices.

SLA can also be used to print nitride-based ceramics, such as silicon nitride (Si3N4) and aluminum nitride (AlN). These materials are characterized by high mechanical strength, thermal stability and outstanding thermal conductivity. Their properties make them ideal candidates for applications requiring extreme thermal and mechanical performance, such as engine and turbine components.

Potentially, most ceramics can be 3D printed using any of the existing technologies.

Yes, at 3DCeram, we have worked on automating the process and have created a recycling station at the printer exit. It receives the printed vat after it has left the printing cycle and filters the formulation that has not been polymerized, so that it can be returned to the printing circuit.

3DCeram has developed its own 3D printing software for its printers.

CPS - Ceramaker Printing Software :

In 2023, an enhanced version was released with the aim of offering greater user comfort for both academic and industrial users.

CPS 2.0 is a user-friendly software package designed to simplify and carry out 3D printing of ceramics, with the aim of preparing print files.
This integrated system offers complete control of the printing process, from design to production.

CPS 2.0 offers an intuitive user interface for preparing 3D files.
The aim is to provide optimized management of printing parameters and real-time control of the printing process. CPS 2.0 performs the analysis and produces a detailed production report.

In 3DCeram's software suite, CPS 2.0 works in harmony with Build-It, a versatile file preparation tool for 3D printing.

Build-It is an easy-to-use plug-in. It allows you to work on the design of the final part and save time on the requirements of the printing process.

Build-It is in fact a kind of toolbox that saves time thanks to its many functions:

- Translation and rotation
- Correction
- Scale factor
- Z compensation
- Print media
- Pockets
- Sides
- Duplicates