UCL Researchers Uncover a New Mechanism of Large Pore Formation During Additive Manufacturing

Professor Peter Lee and Research Fellow Kai Zhang from UCL Mechanical Engineering worked in collaboration with the European Synchrotron Radiation Facility (ESRF), RMIT University (Australia), Shimane University (Japan), Queen Mary University of London and Rolls-Royce plc, along with other colleagues from across UCL. The team assembled at the ESRF to track pores during their formation, growth and migration in situ.

The researchers found that the pore behaviour goes through different stages: formation, bubble coalescence and growth, solid/liquid interface pushing of large bubbles, large bubble entrainment in the molten pool and finally, bubble escape or entrapment.

Professor Lee concluded:

““Only using the higher flux and enhanced beam coherence of the new ESRF Extremely Brilliant Source meant we could replicate industrial conditions to discover that the mechanism of large pore formation is through coalescence of small argon bubbles in the feedstock. The next step is to test ways of mitigating large bubble formation, such as using other feedstocks which don’t have entrained argon bubbles in them.”

Thank you to the ESRF for their article on this study:

Read the full article here

Further Links

• The publication: Zhang, K., Chen, Y., Marussi, S. et al. Nat Commun 15, 1715 (2024). https://doi.org/10.1038/s41467-024-45913-9
• Professor Peter Lee's profile
• The ESRF news article