3D Bioplotter Research Papers

Microlattices with orthogonal 0-90° architecture are 3D-extrusion printed from inks containing a blend of oxide powders (Co3O4, CuO, Fe2O3, and NiO) and metal powder (Cr). Equiatomic CoCrCuFeNi microlattices with ∼170 µm diameter struts are then synthesized by H2-reduction of the oxides followed by sintering and interdiffusion of the resulting metals. These process steps are studied by in-situ synchrotron X-ray diffraction on single extruded microfilaments (lattice struts) with ∼250 µm diameter. After reduction and partial interdiffusion at 600 ˚C for 1 h under H2, filaments consist of lightly-sintered metallic particles with some unreduced Cr2O3. A reduced, nearly fully densified (porosity: 1.6 ± 0.7%)…

Cobalt-based superalloy microlattices were created via (i) three-dimensional-extrusion printing of inks containing a suspension of Co-, Ni- and W-oxide particles, (ii) H2-reduction of the oxides and sintering to a homogenous Co-Ni-W alloy, (iii) Al pack-cementation to deposit Al on the microlattice struts, followed by Al-homogenization. The resulting Co-(18–20)Ni-(5–6)W-(10–13)Al (at.%) microlattices, with 27–30% relative density and 350 μm diameter struts, display a peak in yield strength at 750°C, consistent with their γ/γ′ aged microstructure. Oxidation resistance is strongly improved compared to Al-free printed Co-Ni-W lattices, via the formation of an Al2O3 surface layer. However, the resulting Al depletion within the struts…

Cobalt-based superalloy microlattices with γ/γ′ microstructure are manufactured by combining two additive methods: ink-extrusion 3D-printing and pack-cementation surface alloying. First, a microlattice green structure is 3D-printed at ambient temperature from inks comprised of Co3O4, NiO, and WO3 powders, an elastomeric binder and solvents. Organic removal followed by oxide reduction under Ar-5% H2, sintering and homogenization at 1250 °C lead to a metallic microlattice with dense struts with uniform γ (fcc)-Co–22Ni–8W (at.%) composition. Second, aluminum is deposited on the strut surfaces via pack-cementation at 1000 °C, diffused at 1300 °C through the strut volume to achieve a uniform composition (Co–20Ni–6W–10Al or…