Preliminary testing of nanoparticle effectiveness in binder jetting applications

Binder jetting works by selectively depositing a binder with an inkjet print head into layers of powdered material. Compared with other metal Additive Manufacturing (AM) processes, binder jetting has significant potential for near-term adoption in manufacturing environments due to its reliability and throughput. The Achilles heel of binder jetting, however, is the inability to produce fully dense, single-alloy materials. The lack of density in printed binder jet parts is strictly dictated by the packing factor of the powder feedstock. Adding nanoparticles during printing will not only increase the part’s packing factor but may also serve as a sintering aid. This study focuses on the effect of both the binder and nanoparticles on the final part density. As an unintended consequence of high nanoparticle loading, printed parts underwent a significant increase in porosity during the curing process. This unintended consequence is the apparent result of the nanoparticles blocking the exit of the solvent vapor during the curing step. Additionally, nanoparticle use for densification is validated with SEM imagery.