Forschung für den Mittelstand - Die IGF-Projektdatenbank

Untersuchung der Rissanfälligkeit und Inline-Überwachung des WAAM-Prozesses mit digitalen Methoden

 

 

 

With the additive manufacturing process Wire Arc Additive Manufacturing (WAAM), high build rates can be achieved with comparatively simple technical effort. It is therefore very well suited for SMEs. WAAM can be used for the repair of large components or the production of small series, e.g. in the mobility sector. Here, powder processes reach their limits due to low build-up rates, complex build-ups with lasers and powder handling.

Repeated melting and cooling of the layers leads to complex thermal cycles in the component. This can lead to residual stresses and crack formation. Hot cracks are material and geometry dependent and strongly influenced by the process parameters. As a result, they can neither be predicted nor can general correlations be derived. Statements about hot cracks are only possible qualitatively.

In order to exploit the potential of WAAM for SMEs, they must qualify their materials and processes in terms of application and susceptibility to cracking. This is associated with a high experimental effort. In the DigiWAAM project, a method is to be developed to determine the hot cracking susceptibility of a defined high-alloy steel in additive manufacturing with WAAM in the parameter window. In order to meet challenges in terms of energy and CO2 savings, the scientific approach includes linking the process chain with numerical simulation. This makes it possible to transfer complex iteration cycles into the digital domain.

For the implementation, a validated thermo-mechanical model and material models are created. A forced crack method is developed. It is used to provoke the formation of hot cracks in order to develop and evaluate inline detection methods on them. By applying them, the efficiency of the process can be optimised in terms of deposition rate and welding speed while reducing welding defects.