Implementation of the technology project at two selected demonstrators

 

The two selected demonstrators will result in two lines of development in the course of the project, which will run through all five work packages. The partners Mathys Orthopädie GmbH and Fraunhofer IKTS, together with Fraunhofer IWU, will focus on the development of the knee condyles. Bach Resistor Ceramics GmbH and the IWU will focus on the ceramic heating elements in forming tools made of tool steel. Common to both lines of development is the use of the LBM process to shape the metallic composite component.

 

The project is divided into five work packages (WP): In WP 1, the specifications for the test components and the demonstrators will be developed on the basis of currently existing systems. In the further course of the project, the composite design will be carried out in WP 2. Among other things, macroscopic and microscopic structures for the hybrid composite design will be investigated. In WP 3 the ceramic components, the ATZ (ATZ= Aluminium Toughened Zirconia) component of the knee condyles via the LCM process by IKTS and the ceramic heating elements via conventional shaping by Bach R.C. will be developed and prefabricated for hybridization. In WP 4, the ceramic partial components produced in WP 3 are integrated or completed using the LBM process, so that a characterization of the material composites can be carried out. Finally, the functional hybrid demonstrators are developed, manufactured and analyzed in WP 5.

Figure 1: Presentation of the course of the project and the individual work packages (WP)

Demonstrator condyle of femor

 

The endoprosthetic demonstrator is a ceramic condyle of femor in innovative hybrid construction made of ATZ ceramic and titanium. The articulation side of the condyles is made of ceramic and is produced additively using the LCM process. The side facing the bone consists of porous titanium structures realized by the LBM process. The novel hybrid structure allows for the first time a cement-free anchoring of a ceramic knee condyle over a titanium structure, since a direct osseo integration of ceramic surfaces is not promising.

Demonstrator ceramic heater

 

Ceramic heating elements offer a very good possibility to introduce high energy pulses in a small installation space. With the currently available production technologies, the use of ceramic heating elements is associated with very high production and assembly costs. This effort can be reduced by combining additive manufacturing processes in tool making with the classical manufacturing processes for ceramic heating elements. The demonstrator is intended to provide a basis for the embedding of the heating elements and to enable the creation of tools using this technology.

Technical objectives

 

The individual project partners have the following technical objectives:

 

Mathys Orthopädie GmbH
• Testing the feasibility of a ceramic condyle of femor in hybrid construction made of sustainable ATZ-ceramics and long-term proven titanium

 

Bach Resistor Ceramics GmbH
• Precise integration of heating elements at critical points in the mould to introduce heat locally and enable more precise control of the cavity temperature
• Improvement of the heat transfer between ceramic heater and metal tool
• Improved dynamics of the mould temperature control

 

Fraunhofer IKTS
• Obtaining thicker-walled components via the LCM-process
• Generation of anchor structures for improved connection of a second material component
• Process development for composite material production by hybridization of two additive manufacturing processes

 

Fraunhofer IWU
• Process development for the production of porous titanium structures by laser beam melting
• Process parameter development for the interface area between ceramics and titanium or steel for the production of a material or at least one frictional connection
• Process development for setting defined compressive stresses in steel components