A geopolymeric ink formulation for direct 3D printing containing a geopolymeric formulation whose components are present in such proportions as to be subjected to a geopolymerization reaction and to provide, at the end of the reaction, a solid geopolymer and wherein the formulation, before and during at least a part of the geopolymerization reaction, wherein three-dimensional chemical bonds have not yet been formed, forms a reversible-gel, non-Newtonian, viscoelastic fluid. The formulation is extruded through a 3D printing tool equipped with nozzle into strands according to a geometry such as to create a three-dimensional structure on one or more layers. The extrusion preferably takes place within a hydrophobic liquid, such as oil.

A fast-curing mineral binder mixture includes a zirconium(IV)-based accelerator, a cement which includes at least one component selected from the compounds 3CaO*Al.sub.2O.sub.3, 12CaO*7Al.sub.2O.sub.3, CaO*Al.sub.2O.sub.3, CaO*2Al.sub.2O.sub.3, CaO*6Al.sub.2O.sub.3 and 4CaO*3Al.sub.2O.sub.3*SO.sub.3, and 15 to 80 wt % of a sulfate carrier, wherein the wt % is based on a weight of the fast-curing mineral binder mixture. The fast-curing mineral binder mixture can optionally include at least one alkaline component and/or at least one additive.

A method for making an article comprising silicon carbide. The method includes producing an article including silicon carbide via additive manufacturing. The method further includes heating via at least one laser beam in a site-selective and locally limited manner a surface of the article so as to cause at least one of ablation and chemical modification of the surface.

A method for preparing a slurry for photocuring 3D printing is provided, comprising the steps of: mixing monomer molecules of a thermosensitive hydrogel, a photocuring initiator, a crosslinking agent, a solvent, and a ceramic material to obtain the slurry. a method for manufacturing photocuring 3D printed articles is further provided, comprising using the slurry as a raw material, performing a 3D printing procedure by a photocuring 3D printer to obtain a green compact of a 3D printed article; and coating oil to the green compact of the 3D printed article, followed by heating and sintering the oil-coated article, to obtain the 3D printed article.

A 3D printable clay-based mortar cementitious ink includes a blend of commercially available Portland cement, calcium carbonate, sand, and calcined clay. The calcined clay is produced from the calcination of clay having a high kaolinite content of greater than about 60%. The clay is calcined at a temperature of between about 600° C. and about 800° C., preferably between about 650° C. and about 850° C., for a period of one to two hours. In a preferred embodiment, a ratio of calcined clay to Portland cement is about 0.148, a ratio of calcium carbonate to Portland cement is about 0.333, and a ratio of sand to Portland cement is approximately about 3.0. The ratio of water to powder (clay, cement, calcium carbonate, and sand) may range between 0.39 and 0.40.

An electromagnetic interference (EMI) resistant cementitious ink comprising a hydraulic cement, calcium carbonate, silica sand, taconite material, and a conductive material. A ratio of the silica sand to the taconite material is 1:1. In some embodiments, the taconite material includes taconite powder and fine taconite aggregate having a ratio of 1:1. In some embodiments, the conductive material includes carbon-based nanoparticles in solution. In further embodiments, the EMI-resistant cementitious ink has a shielding effectiveness in accordance with ASTM D4935-18 of at least 4.0 dB.

Disclosed herein are embodiments of a printable composition that can be used to make printed products of a chosen material chemistry that have different levels of porosity within the printed product's structure Also disclosed herein are embodiments of a printed product that has multiple levels of porosity throughout its structure, which can include a macroscale level of porosity, a microscale level of porosity, a nanoscale level of porosity and any combination thereof. These printed products can be made using a 3-D printer and can be made from a single printable composition without the need to add different structural components during the production process. Also disclosed herein are embodiments of a method for making and using a printed product.

A cementitious print head and a cementitious printing methodology may include a feed barrel, a print head nozzle, a CO.sub.2 supply, a steam supply, a selective valve assembly in communication with the CO.sub.2 supply and the steam supply, a plurality of dual use extrusion head injectors, and a print head controller. The print head controller is operatively coupled to the selective valve assembly and is programmed to execute a CO.sub.2 and steam injection protocol where steam may be selected for injection by the extrusion head injectors into a cementitious composition as it is extruded from the print head nozzle to enhance a hydration reaction and formation of hydroxide in the cementitious composition before CO.sub.2 may be selected for injection by the extrusion head injectors into the cementitious composition as it is extruded from the print head nozzle to enhance a carbonation reaction in the cementitious composition.

An exemplary process for forming a cured hybrid magnesium cement composition may include first combining a mixture of magnesium-containing material, a metal silicate inorganic polymer having a repeat unit of SiP.sub.2O.sub.7, and a salt having a non-metallic oxide anion, and then mixing the mixture with water.

A cementitious mixture for a 3D printer and its relative use are described, more specifically for the production of finished products having a complex geometry using a 3D printing apparatus.