Binder jetting additive manufacturing with a particle-free metal ink as a binder precursor. (5th June 2018)

• Record Type: Journal Article
• Authors: Bai, Yun; Williams, Christopher B.
• Is Part Of: Materials & design. Volume 147(2018)
• Page Start: 146
• Page End: 156
• Publication Date: 2018-06-05
• Subjects: MOD ink -- Nanoparticle -- Inkjet printing -- Binder jetting -- Additive manufacturing -- Copper; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2018.03.027
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Metal-Organic-Decomposition (MOD) ink is a particle-free metal ink that can precipitate metal nanoparticles upon heating. This ink-jettable metal nanoparticle ink can be used as a binder precursor to replace commonly used polymer adhesives in the Additive Manufacturing of metals components using binder jetting technology. After being deposited into the powder bed interstices and exposed to a heat, the jetted ink decomposes and form metal nanoparticles that are then fused by sintering to provide bonding strength to the printed parts. Regions of the powder bed that do not receive the jetted nanoparticles remain as loose powder, as the heat supplied to sinter nanoparticles is maintained below the initial sintering temperature of larger powder bed particles. The proof of concept is demonstrated in the context of printing copper by jetting copper MOD ink as a precursor to the binder, with the capability of producing satisfactory geometries when using sufficiently high binder saturation ratio. After sintering, the MOD ink printed parts produce a denser core section but more porous shell in the sintered parts, compared to the polymer binder printed counterparts. Graphical abstract: Unlabelled Image Highlights: Powder bonding is formed by sintered nanoparticles, which are precipitated from MOD ink jetted as a binder precursor. Compared to nanoparticle suspensions, MOD ink is particle free and therefore less challenging to inkjet print. Sintering of MOD ink printed copper coupons produces less porosity in the core section of the sintered parts.