Researchers at UCL Mechanical Engineering have identified two new mechanisms that cause spatter formation in metal Laser Powder Bed Fusion (LPBF). The team, led by Prof. Lee and Dr. Leung, used high-speed X-ray imaging to study how tiny particles form during the printing process and contribute to surface defects in printed components.
Spatter formation remains a significant challenge in LPBF technology, where small particles can create surface defects and porosity that weaken printed parts. These issues make components unsuitable for critical applications in aerospace and energy industries. Additionally, spatter particles can oxidize and reduce the recyclability of unused metal powder.
The research team used a custom-built machine called the Quad-laser in situ and operando process replicator (Quad-ISOPR), equipped with four lasers and an industrial scan head system from Renishaw Plc. The machine features an argon gas-filled chamber designed to create optimal printing conditions for metal components.
By combining their custom machine with high-speed X-ray imaging at the European Synchrotron Radiation Facility (ESRF), researchers captured detailed images at 40,000 frames per second. This imaging speed allowed them to observe spatter dynamics and molten metal pool behavior during the printing process with unprecedented detail.
The team’s observations of these newly identified spatter mechanisms have led to proposed strategies for reducing defects and improving surface quality in printed parts. The research findings could contribute to improved LPBF processes for manufacturing critical components in aerospace and energy applications.
Source: ucl.ac.uk