Design of Binders for Binder Jet Additive Manufacturing

Binder jet additive manufacturing (BJAM) is a versatile AM technique that presents an avenue for advanced manufacturing of powdered materials, including metals, ceramics, and polymers, with high-deposition rates, scalability, and geometric flexibility. BJAM uses ink-jet technology to deposit a binding fluid (binder) into layers of powdered metal, ceramic, or polymeric materials. However, the industrial application of BJAM is currently limited in various applications due to adverse effects from the binder. Despite the fundamental importance of the binders for successful BJAM, the understanding and engineering of the binder is often overlooked. The binder is a determining factor for initial preform formation, processability, and final characteristics of the printed parts in the BJAM process. The development of binders in BJAM is complex and has many competing demands, such as the need for specific rheological properties, stability, and favorable interaction with the powder system. Additionally, the residual carbon left by most binders is important to control in the process since it affects the final part's chemistry and geometry. Therefore, developing a deeper understanding of physicochemical principles of the binder will allow for greater adoption of BJAM in the current and future applications for advanced manufacturing of materials with better properties, structures, and functions.