Real time observation of binder jetting printing process using high-speed X-ray imaging

Area of Science:

• Materials Science
• Mechanical Engineering
• Manufacturing Technology

Background:

• Binder jetting is a key additive manufacturing (AM) process.
• Understanding droplet dynamics and powder interactions is crucial for process optimization.

Purpose of the Study:

• To investigate the binder jetting AM process using high-speed synchrotron X-ray imaging.
• To analyze droplet formation, satellite droplets, and powder bed interactions in real-time.

Main Methods:

• Utilized a commercial binder jetting printer with a droplet-on-demand ink-jet print-head.
• Employed high-speed synchrotron X-ray imaging to record the printing process in real-time.
• Analyzed droplet shape, satellite droplet behavior, and powder particle movement upon impact.

Main Results:

• Observed ink-jet droplets with elongated shapes, spherical heads, long tails, and 3-5 satellite droplets.
• Documented significant drift between main and satellite droplet impact points.
• Identified powder particle movement and ejection upon droplet impact, defining an 'interaction depth' dependent on powder characteristics.
• Noted coalescence of binder droplets for fine powders (<10 μm) forming agglomerates.

Conclusions:

• The study provides fundamental insights into the physics governing binder jetting.
• These findings can guide improvements in part quality for binder jetting additive manufacturing.
• Real-time X-ray imaging is a powerful tool for analyzing AM processes.