Attractive

Aims of the project

The R&D project is concerned with the development of computer-aided combined additive and subtractive production planning of structurally optimized lightweight components. The market for metal-processing additive manufacturing is growing very rapidly. Subtractive post-processing of high-precision functional surfaces is essential here. In the aerospace, automotive and medical technology sectors, there is a growing demand for structurally optimized lightweight components that have low masses with high mechanical strength and can be combined into complex assemblies using high-precision functional elements. An intelligent combination of metal-based additive manufacturing and state-of-the-art CNC post-processing is required to achieve these targets in line with market requirements. The highest demands are placed on the production parts in terms of their component design and the accuracy of the connected functional elements. Due to the particularly high cost of subtractive post-processing of complex additive components, the cost of the finished component can quickly double.

The main problems are

• Need for expert knowledge: Both areas, additive manufacturing (AM) and subtractive manufacturing (SM), require specific expert knowledge as well as a high degree of experience for the corresponding production planning.
• No or insufficient exchange of information: Additive manufacturing planning is typically carried out without the inclusion of subtractive post-processing planning. Although this can optimize the additive planning process, the subsequent subtractive post-processing process can be extremely time-consuming.
• Complex development of component-specific special clamping devices: Structurally optimized lightweight components often do not allow the use of regular clamping devices. Instead, component-specific special clamping devices must be developed at great expense for each clamping orientation.
• High time and personnel costs in the subtractive set-up process: There are no defined support, clamping and referencing areas in the additive component design, which means that time-consuming set-up processes for the individual special clamping devices are required.
• Surface quality of machined AM components: In the additive planning process, support structures are designed with regard to the required strength and thermal conductivity. However, machine removability is not taken into account, which means that fluctuating cutting forces can influence the surface quality.
• Risk of deformation: When clamping the components, there is a risk that they may deform, as the clamping forces are often not taken into account in the component design. Possible consequences here are component deformation, which affects component functionality, as well as stress corrosion cracking, which can even lead to premature component failure.
• No joint computer support: The two planning processes are currently carried out independently of each other in their respective software tools. Computer support for the combined additive-subtractive planning process is currently not available. The innovation of this industrial R&D project is to take the subtractive post-processing of AM structural components into account in additive manufacturing planning by means of end-to-end computer support, thereby optimizing the planning process in its entirety. The main advantages of this approach are
• The subtractive post-processing process is optimized through combined planning, which significantly saves time and costs.
• The optimized subtractive planning process significantly increases the dimensional accuracy and surface quality of structurally optimized AM components.
• The time-consuming development of special clamping devices is completely eliminated. For the finishing process, only standardized clamping and referencing elements (yet to be developed) are required, which are integrated into the component and/or the support structure.