Hewlett-packard Development Company, L.P.

Paul Olubummo

Lihua Zhao

Aja Hartman

Howard S Tom

Kristopher J Erickson

Krzysztof Nauka

Yan Zhao

In an example, a three-dimensional (3D) printed part comprises a plurality of fused build material layers including exterior layers and interior layers. At least some of the interior layers include a composite portion having a miscible solid physically bonded to an amide functionality or an amine functionality of the build material. The miscible solid is a solid at a room temperature ranging from about 18&#xb0; C. to about 25&#xb0; C.

Three-dimensional printed part

The present disclosure is drawn to a three-dimensional printing system can include a powder bed material, including from 80 wt % to 100 wt % metal particles having a D50 particle size distribution value ranging from 5 &#x3bc;m to 75 &#x3bc;m and a powder bed support substrate for receiving the powder bed material. The system can also include a fluid ejector operable to digitally deposit a thermally sensitive binder fluid onto a selected portion of the powder bed material on the powder bed support substrate. The thermally sensitive binder fluid can include water, a reducible metal compound, and a thermally activated reducing agent. A light source can also be present to generate a pulse energy sufficient to cause the thermally activated reducing agent to reduce the reducible metal compound and bind metal particles together to form a green three-dimensional part.

Three-dimensional printing systems

An example of a fusing agent includes a metal bis(dithiolene) salt, a polar aprotic solvent, and a balance of water. An example of a method for making an example of the fusing agent includes adding a metal bis(dithiolene) salt into a liquid vehicle including at least a polar aprotic solvent and water.

Fusing agent including a metal bis(dithiolene) salt

A three-dimensional printing system can include polymeric build material and jettable fluid(s). The polymeric build material can have an average particle size from 20 &#x3bc;m to 150 &#x3bc;m, a first melt viscosity, and a melting temperature from 75&#xb0; C. to 350&#xb0; C. In one example, the jettable fluid can include water, from 0.1 wt % to 10 wt % of electromagnetic radiation absorber, and from 10 wt % to 35 wt % of an organic solvent plasticizer. Contacting a first portion of a layer of the polymeric build material with the jettable fluid can provide an organic solvent plasticizer loading from 2 wt % to 10 wt % based on the polymeric build material content. The first melt viscosity of the polymeric build material at the first portion can be reduced and the melting temperature of the polymeric build material at the first portion can be decreased by 3&#xb0; C. to 15&#xb0; C.

Three-dimensional printing

An example of a fusing agent includes a tetraphenyldiamine-based dye, alkyldiphenyloxide disulfonate, 1-methyl-2-pyrrolidone, and a balance of water. The fusing agent excludes a strong reducing species. The fusing agent may be incorporated into a three-dimensional printing method or a three-dimensional printing system. In an example of the three-dimensional printing method, a polymeric or polymeric composite build material is applied. The fusing agent is selectively applied on at least a portion of the polymeric or polymeric composite build material. The polymeric or polymeric composite build material is exposed to electromagnetic radiation to fuse the portion of the polymeric or polymeric composite build material in contact with the fusing agent to form a layer.

Fusing agent including a tetraphenyldiamine-based dye

In an example of a three-dimensional (3D) printing method, a polymeric or polymeric composite build material is applied. A fusing agent is selectively applied on at least a portion of the polymeric or polymeric composite build material. The fusing agent includes a discolorable near-infrared absorbing dye, a thiol surfactant, a reducing agent, and a balance of water. Near-infrared radiation is applied to the polymeric or polymeric composite build material at a condition that maintains a temperature of the selectively applied fusing agent below a decomposition temperature of the fusing agent and that allows the discolorable near-infrared absorbing dye to harvest near-infrared radiation energy, in order to fuse the portion of the polymeric or polymeric composite build material in contact with the fusing agent to form a layer and to initiate discoloration of the discolorable near-infrared absorbing dye in the layer.

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Palo Alto, CA, United States of America

Paul Olubummo