Fraunhofer IKTS scientists have developed a Multi Material Jetting (MMJ) system that combines different materials into a single additively manufactured part.
According to the scientists, the new system can be used with high-performance materials such as ceramics and metal, and it ensures that these materials’ properties are intact in the final product.
“Right now, we can process up to four different materials at a time,” says IKTS researcher Uwe Scheithauer.
This should enable companies to produce applications with both: 1) highly integrated multi-functional components and 2) individually defined properties.
According to the IKTS team, the new system fabricates parts in a continuous process.
In the first step, the ceramic or metal powder from which the part will be made is distributed homogenously in a thermoplastic binder substance.
The slurries produced in this way are loaded into micro-dosing systems (MDS) in order to commence the actual manufacturing process.
These slurries are then melted in the MDS at a temperature of around 100 degrees Celsius, creating a substance that can be released in very small droplets.
The scientists have also developed a corresponding software program to ensure precise positioning of the droplets during manufacturing.
This ensures that the micro-dosing systems operate in a high-precision, computer-controlled process, depositing the droplets one by one in exactly the right spot.
The system then gradually builds up the part drop by drop at rates of up to 60 mm and 1,000 drops a second.
It can work with droplet sizes of between 300 and 1000 μm, and is capable of creating deposited layers with heights of between 100 and 200 μm.
According to Scheithauer, the maximum size of parts that can be currently manufactured is 20 × 20 × 18 centimeters.
“The critical factor here is the custom dosing of the metal or ceramic slurries,” says Scheithauer.
“Getting the dosing right is key to ensuring that the additively manufactured final product takes on the required properties and functions during subsequent sintering in the furnace, including properties such as strength, thermal conductivity and electrical conductivity.”
According to the scientists, the new system could revolutionize the way satellite propulsion engines are made.
It could also be used to make individualized items such as two-tone ceramic watch bezel, and blanks for carbide parts that usually require strenuous grinding.
Image and content: Fraunhofer IKTS