Duration: 36 months
Laser powder bed fusion (LPBF) technology fuses powder particles into components, layer-by-layer, directly from a digital file. LPBF can manufacture topologically optimised parts with a high buy-to-fly ratio, reducing the payload for aerospace components. Though, LPBF parts suffer from process-induced defects and exhibits poor surface finish, lowering their fatigue performance. Poor surface finish can be non-compliant with the cleanliness requirements of space application. Post-processing techniques, such as hot isostatic pressing, chemical milling, and machining, may improve the built quality though they are costly and energy intensive processes.
To ensure the build process reaches the net-zero emission target and production of high-quality aerospace components without post-processing, we must study the process and defect dynamics during LPBF and develop a manufacturing framework that makes LPBF parts cost-effectively and sustainably.
Here, we propose
- using pulse shaping strategies to minimise the metal vaporisation during LPBF of alloys (with a low coefficient of thermal expansion) to produce defect-free parts with smooth surface;
- the process dynamics above and inside the melt pool will be observed during LPBF using a physical twin of the RenAM500Q machine equipped with multi-modal optical, chemical, infrared, and ultra-fast X-ray imaging capabilities at European Synchrotron radiation Facilities.
- feeding these experimental data into an existing high-fidelity simulation tool (a digital twin, co-developed by UCL & ESA) to predict the melt pool and defect dynamics during LPBF.
- We will extract further key physics from the physical & digital twins to run low fidelity surrogate simulation models as a virtual testing platform for determining optimum processing parameters to produce high-quality parts.
- Lastly, we will verify the virtual testing platform by producing large-scale parts with user-defined surface roughness using a commercial LPBF system.
