Abstract: The present disclosure describes three-dimensional printing kits, three-dimensional printing systems, and methods of making three-dimensional printed objects. In one example, a three-dimensional printing kit can include a build material and a binding agent. The build material can include particles of copper or a copper alloy. The binding agent can include water, copper (II) nitrate or a hydrate thereof, and a reaction inhibition additive. The additive can be a copper oxide etchant, a water-soluble phosphate-containing compound, or a combination thereof.

Abstract: A computing device comprising a controller is disclosed herein. The controller is to access print data of a virtual build volume including a 3D object to be generated by a 3D printer; modify the print data to include a 3D structure at a location within the build volume to encapsulate an amount of build material; receive powder degradation data corresponding to the powder degradation of the encapsulated amount of build material; and calibrate an additive manufacturing parameter based on the powder degradation data.

Abstract: A 3D printing kit can include a powder bed material comprising from about 80 wt % to 100 wt % polymer particles, a fusing agent to selectively apply to the powder bed material, and a hardener to selectively apply to the powder bed material. The polymeric particles can include a polyalkylene backbone with both ethylene and propylene polymerized monomeric units with from 2 mol % to 15 mol % of the polymerized monomeric units include a grafted side chain having an epoxide moiety. The fusing agent can include water and a radiation absorber that absorbs electromagnetic energy and converts the electromagnetic energy to heat. The hardener can be present in the fusing agent or can be included in a hardening agent that is separate from the fusing agent.

Abstract: An example of a kit for three-dimensional (3D) printing includes an ultraviolet (UV) light fusing agent. The ultraviolet (UV) light fusing agent includes an aqueous vehicle and a B vitamin or a B vitamin derivative present in an amount that dissolves in the aqueous vehicle. The aqueous vehicle includes a co-solvent, a surfactant, and water. The B vitamin or the B vitamin derivative has absorption at wavelengths ranging from about 340 nm to about 415 nm.

Abstract: The present disclosure is drawn to multi-fluid kits for three-dimensional to printing, three-dimensional printing kits, and methods of making three-dimensional printed articles. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent, a first reactive agent, and a second reactive agent. The fusing agent can include water and a radiation absorber. The first reactive agent can include a first liquid vehicle and an epoxy compound having multiple epoxide groups. The second reactive agent can include a second liquid vehicle and an amine compound having multiple amino groups.

Abstract: The present disclosure is drawn to multi-fluid kits for three-dimensional to printing, three-dimensional printing kits, and methods of making three-dimensional printed articles. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent, a first reactive agent, and a second reactive agent. The fusing agent can include water and a radiation absorber. The first reactive agent can include a first liquid vehicle and an epoxy compound having multiple epoxide groups. The second reactive agent can include a second liquid vehicle and an amine compound having multiple amino groups.

Abstract: The present disclosure relates to a kit for 3D printing a 3D printed metal object. The kit comprises build material comprising metal particles; and a binding agent. The binding agent comprises a hydrated metal salt having a dehydration temperature of from 100 to about 250° C., and water. The binding agent may be either free from organic solvent and surfactant, or the binding agent comprises organic solvent and/or surfactant and the total amount of organic solvent and/or surfactant is less than 3 weight % based on the total weight of the binding agent.

Abstract: The present disclosure is drawn to multi-fluid kits for three-dimensional printing, three-dimensional printing kits, and methods of making three-dimensional printed articles. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent, a first reactive agent, and a second reactive agent. The fusing agent can include water and a radiation absorber. The first reactive agent can include a first liquid vehicle and an epoxy compound having multiple epoxide groups. The second reactive agent can include a second liquid vehicle and an amine compound having multiple amino groups.

Abstract: A three-dimensional printing kit can include a particulate build material, a binding agent, and a supportive coating agent. The particulate build material can include from about 80 wt % to about 100 wt % metal particles based on the total weight of the particulate build material. The binding agent can include binder particles dispersed in a binder liquid vehicle. The supportive coating agent can include ceramic particles having a negative coefficient of thermal expansion, a gelling compound, and a supportive coating liquid vehicle.

Abstract: In an example of a method for three-dimensional (3D) printing, a build material composition is applied to form a build material layer. The build material composition includes a polyamide. The polyamide is selectively melted, based on a 3D object model, in at least a portion of the build material layer to form a molten portion including molten polyamide. An epoxy agent is selectively applied, based on the 3D object model, on the molten portion of the build material layer. The epoxy agent includes a polyfunctional epoxy, which crosslinks the molten polyamide in the molten portion.

Abstract: A 3D printing kit can include a powder bed material comprising from about 80 wt % to 100 wt % polymer particles, a fusing agent to selectively apply to the powder bed material, and a hardener to selectively apply to the powder bed material. The polymeric particles can include a polyalkylene backbone with both ethylene and propylene polymerized monomeric units with from 2 mol % to 15 mol % of the polymerized monomeric units include a grafted side chain having an epoxide moiety. The fusing agent can include water and a radiation absorber that absorbs electromagnetic energy and converts the electromagnetic energy to heat. The hardener can be present in the fusing agent or can be included in a hardening agent that is separate from the fusing agent.

Abstract: The present disclosure relates to a three-dimensional (3D) printing materials kit comprising: a first tailoring agent comprising at least one crosslinking agent; a second tailoring agent comprising at least one plasticizer, and a fusing agent. The present disclosure also relates to a printed structure comprising regions of relatively higher ductility and regions of relatively lower ductility. The regions of relatively higher ductility can be interspersed by the regions of relatively lower ductility, and the regions of relatively lower ductility can be formed from a crosslinked polymer and/or a polymer composition comprising a reinforcing filler, and/or the regions of relatively higher ductility can be formed from a polymer composition comprising a plasticizer. The present disclosure also relates to a method of three dimensional printing (3D) that can be used to print a 3D printed object comprising the printed structure described above.

Abstract: The present disclosure is drawn to multi-fluid kits for three-dimensional printing, three-dimensional printing kits, and methods of making three-dimensional printed articles. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent, a first reactive agent, and a second reactive agent. The fusing agent can include water and a radiation absorber. The first reactive agent can include a first liquid vehicle and an epoxy compound having multiple epoxide groups. The second reactive agent can include a second liquid vehicle and an amine compound having multiple amino groups.

Abstract: In an example of a method for three-dimensional (3D) printing, a build material composition is applied to form a build material layer. The build material composition includes a polyamide. The polyamide is selectively melted, based on a 3D object model, in at least a portion of the build material layer to form a molten portion including molten polyamide. An epoxy agent is selectively applied, based on the 3D object model, on the molten portion of the build material layer. The epoxy agent includes a polyfunctional epoxy, which crosslinks the molten polyamide in the molten portion.