# US 10,478,994 B2 · Fabricating a three-dimensional object > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,478,994 B2 - Document ID: US10478994B2 - Status: Granted - Kind: B2 - Application number: 15/512,422 - Filed: 2014-10-08 - Published: 2017-08-31 - Granted: 2019-11-19 - Earliest claimed: 2014-10-08 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Hewlett-Packard Development Company, L.P. - Inventors: David A. Champion; James Elmer Abbott, Jr. - Web page: https://patentgrep.com/patent/US10478994B2 ## CPC - B28B 1/001: {Rapid manufacturing of 3D objects by additive depositing, agglomerating or laminating of material (selective deposition modelling of metallic powder B22F10/00; rapid manufacturing of 3D objects in general and in particular of plastics B29C64/00)} - B28B 11/241: {using microwave heating means} - B28B 17/0081: {Process control} - B29C 64/165: using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber - B29C 64/209: Heads; Nozzles - B29C 64/291: for operating globally, e.g. together with selectively applied activators or inhibitors - B33Y 10/00: Processes of additive manufacturing - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - B33Y 50/02: for controlling or regulating additive manufacturing processes - B33Y 70/00: Materials specially adapted for additive manufacturing - B28B: SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER (foundry moulding B22C; working stone or stone-like material B28D; shaping of substances in a plastic state, in general B29C; making layered products not composed wholly of these substances B32B) - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING ## Abstract In one example, a method of fabricating a three-dimensional object includes depositing a layer of build material, depositing a coalescing agent onto the layer of build material according to a slice of three-dimensional model data, irradiating the coalescing agent with microwave radiation such that the coalescing agent converts the microwave radiation into heat to coalesce the build material in which the coalescing agent was deposited. ## Claims ### Claim 1 A method of fabricating a three-dimensional object, comprising: depositing a layer of build material; depositing a coalescing agent onto the layer of build material according to a slice of three-dimensional model data; and irradiating the coalescing agent with microwave radiation such that the coalescing agent converts the microwave radiation into heat to coalesce the build material in which the coalescing agent was deposited; wherein irradiating the coalescing agent comprises irradiating the coalescing agent with a first microwave radiation to partially coalesce the build material prior to irradiating the coalescing agent with a second relatively more intense microwave radiation to fully coalesce the build material. ### Claim 2 (depends on 1) The method of claim 1, wherein the build material is substantially transparent to the radiation. ### Claim 3 (depends on 1) The method of claim 1, wherein the coalescing agent in each individual layer of build material is irradiated with the first microwave radiation and the coalescing agent in all of the layers of build material is irradiated together with the second microwave radiation. ### Claim 4 (depends on 1) The method of claim 1, wherein the coalescing agent in each layer of build material is irradiated before a successive layer of build material and coalescing agent is deposited. ### Claim 5 (depends on 1) The method of claim 1, wherein the coalescing agent in each layer of build material is deposited for the entire three-dimensional object before the layers are irradiated. ### Claim 6 (depends on 1) The method of claim 1, wherein the build material comprises any of a ceramic, glass and metal oxide. ### Claim 7 (depends on 1) The method of claim 1, wherein the coalescing agent comprises any of carbon black, graphite and metallic nanoparticles. ### Claim 8 (depends on 1) The method of claim 1, further comprising using a data storage device and an apparatus to generate a three-dimensional object, comprising: a coalescing agent depositor; a build material layer depositor; a processor; and the data storage device communicatively coupled to the processor; the method comprising, with the processor, executing computer code to control the coalescing agent depositor to deposit an amount of coalescing agent onto a layer of build material according to a three-dimensional model data stored in the data storage device, the build material being transparent to microwave radiation; and the processor to execute computer code to control the coalescing agent depositor and build material layer depositor so that each layer of coalescing agent and build material is deposited for the entire three-dimensional object before the layers are irradiated with microwave radiation. ### Claim 9 (depends on 8) The method of claim 8, wherein the build material is ceramic. ### Claim 10 (depends on 8) The method of claim 8, wherein the coalescing agent comprises any of carbon black, graphite and metallic nanoparticles. ### Claim 11 (depends on 8) The method of claim 8, further comprising moving the layers of build material and coalescing agent representing the entire three-dimensional object into a microwave furnace for irradiation. ### Claim 12 (depends on 1) The method of claim 1, further comprising depositing a range of differently diluted coalescing agent with more-concentrated coalescing agent being applied at locations of the build material where a higher degree of coalescence is desired. ### Claim 13 (depends on 1) The method of claim 1, further comprising depositing a relatively greater quantity of coalescing agent to the build material at locations where a higher degree of coalescence is desired. ### Claim 14 (depends on 1) The method of claim 1, further comprising heating the coalescing agent prior to the coalescing agent being deposited to the build material. ### Claim 15 (depends on 1) The method of claim 1, wherein the coalescing agent comprises any of: nanoglass, nano-oxides and iron ferrite.