Novel hybrid method to additively manufacture denser graphite structures using Binder Jetting

Area of Science:

• Materials Science
• Manufacturing Engineering
• Additive Manufacturing

Background:

• Traditional additive manufacturing methods like Binder Jetting Printing (BJP) often result in parts with high porosity and lower density.
• Post-processing treatments are crucial for enhancing the mechanical properties and structural integrity of additively manufactured components.

Purpose of the Study:

• To introduce and evaluate two novel hybrid additive manufacturing processes.
• To improve the density and reduce defects in additively manufactured parts using BJP combined with post-processing.
• To investigate the fabrication of graphite structures using these hybrid methods.

Main Methods:

• Development of two hybrid processes: (i) Binder Jetting Printing (BJP) + Cold Isostatic Pressing (CIP) + cycle (Impregnation-Drying-Pyrolysis) and (ii) BJP + cycle.
• Fabrication of graphite structures using the developed hybrid processes.
• Benchmarking against BJP alone and traditional compaction molding.
• Comprehensive characterization of microstructure and mechanical properties.

Main Results:

• The hybrid processes significantly reduced porosity in manufactured graphite structures from 55% to a record low of 7%.
• Additively manufactured parts exhibited higher density compared to conventional methods.
• Microstructure and mechanical property analyses confirmed the improvements achieved through the hybrid approach.

Conclusions:

• The developed hybrid additive manufacturing processes offer a viable pathway to produce high-density, low-porosity components.
• This technological advancement is poised to unlock new industrial applications for BJP-based hybrid manufacturing.
• The study demonstrates a significant improvement in material quality for additively manufactured parts.