Determining Hot Cracking Susceptibility in Additive Manufacturing using Modeling and Experimentation

Purpose and goal:

Additive manufacturing (AM) of large components in Ni-superalloy using laser and wire (LDED-w) is a key method for sustainable production of aircraft engines enabling the lowering of CO2 emission and the transition to fossil-free fuels. However, this production is still hindered due to hot cracking defects.

This project, with the focus area Integrated structure, materials, and production technology, aims to gain insight into the formation of this defect and develop models and simulation tools to predict hot cracking susceptibility in produced components. Expected results and effects: The results will include

- a detailed multi-physics model coupling the melt pool, metal transfer, solidification, and semi-solid deformation to establish a hot cracking criterion, - a full-scale model to predict hot cracking in a simple manufactured component, - a reliability evaluation of both models.

They will contribute to reducing costly trial-and-error tests, and mature LDED-w that opens up sustainable and robust production of high-quality parts and thus strengthen the competitiveness of the Swedish aviation industry. Approach and implementation:

To achieve this, complementary areas of competence in AM and Ni-superalloy will be set together with Högskolan Väst (coordinator) thermo-fluid modelling, in-situ instrumentation, hot cracking analysis, KTH solidification and microstructure, LTU solid state mechanics, GKN Aerospace Swedish worldwide manufacturer of aircraft engines, and PROCADA AB Swedish SME expert in process control. Experiments will be done to validate the models and a demonstrator will be analyzed.

The project is estimated to last four years, with a total cost of 12.45 MSEK.