Patent Description:
Three-dimensional (3D) printing is an additive manufacturing process that allows for the manufacture of objects by "building up" an object. In contrast to subtractive techniques, such as machining, in which material is removed from a bulk material in order to form the shape of an object, 3D printing lays down successive layers of material to form the shape of an object. Typical materials used for 3D printing may include plastics, ceramics, and metals.

<CIT>, <CIT> and <CIT> also relate to methods for additive manufacture.

The present invention concerns a method for additive manufacture in accordance with claim <NUM>. Preferred embodiments are defined in claims <NUM> and <NUM>.

Technical advantages of certain embodiments may include using a negative electron affinity nanoparticle with halogenated solution to form a ceramic without a greenware intermediary that requires heating with a kiln to form a final ceramic. Some embodiments may include forming a polycrystalline diamond. Other embodiments may include forming a mixed carbon hybrid orbital ceramic. Yet other embodiments may include forming a silicon carbide ceramic. Other technical advantages will be readily apparent to one skilled in the art from the following figures, descriptions, and claims. Moreover, while specific advantages may have been enumerated above, various embodiments may include all, some, or none of the enumerated advantages.

For a more complete understanding of the disclosed embodiments and their features and advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:.

Embodiments of the present disclosure and its advantages are best understood by referring to <FIG>, like numerals being used for like and corresponding parts of the various drawings.

Current techniques of 3D printing ceramics require use of a preceramic polymer or ceramic-particles-plus binder to create a greenware intermediary. The greenware intermediary requires heating, often through use of a kiln, to thermolyze or sinter into a final ceramic. Heating the greenware intermediary in the kiln causes shrinkage, which must be anticipated during the design of the product.

In order to eliminate the greenware intermediary that requires heating in the kiln, embodiments of the present disclosure include 3D printing a ceramic by inducing a negative electron affinity nanoparticle in a halogenated solution to emit electrons, where the reduced halocompound nucleates to directly form the ceramic. By 3D printing a ceramic with a negative electron affinity nanoparticle and a halogenated solution, the ceramic may be formed without the greenware intermediary that requires baking or sintering in a kiln. The 3D printing with a negative electron affinity nanoparticle and halogenated solution also avoids contaminant in the form of a catalyst or binder, because the nanoparticle is incorporated directly into the ceramic product. Embodiments of the present disclosure may also include forming a 3D ceramic of arbitrary shape at room temperature or lower.

Diamond is a form of the element carbon that has many unique properties. Diamond is among the hardest known materials, has a high melting and boiling point, and is an excellent thermal conductor as well as electrical insulator. Objects made out of diamond may be able to take advantage of these properties. For example, tools made out of diamond, such as drill bits, saws, or knives, may be more durable than tools made of conventional materials due to the hardness of diamond. Diamond can be produced in a variety of ways including as a powder in the form of diamond nanoparticles and from the pyrolysis of a pre-ceramic polymer.

The teachings of this disclosure recognize that using three-dimensional (3D) printing techniques with a negative electron affinity nanoparticle and a halogenated solution may allow for the creation of objects made of a variety of ceramics in a variety of useful shapes. In particular, using 3D printing techniques with a negative electron affinity nanoparticle (for example, a hydrogen-terminated nanodiamond) and a halogenated solution (for example, carbon tetrachloride) may allow for the creation of diamond objects in a variety of shapes. For example, using 3D printing with a negative electron affinity nanoparticle (for example, a nanodiamond) and a halogenated solution (for example, carbon tetrachloride) may allow for the creation of a diamond drill bit having almost any geometry. As other examples, 3D printing with a negative electron affinity nanoparticle (for example, nanodiamond) and a halogenated solution (for example, carbon tetrachloride) may be used to print brake pad inserts, avionics boxes, lightweight armor, diamond dialysis filters, vacuum micro-electronics, or any other appropriate object.

Further, by using different negative electron affinity nanoparticles and halogenated solutions separately or in addition to nanodiamond or carbon tetrachloride, the properties of a printed object could be varied to meet various design objectives. For example, in addition to forming diamond objects, embodiments of the present disclosure may form objects made of other carbides, such as silicon carbide, titanium carbide, hafnium carbide, vanadium carbide, or tungsten carbide. Embodiments of the present disclosure may also form objects made of boron nitride. Yet other embodiments of the present disclosure may form objects made of mixed hybrid orbital carbon, for example carbyne-doped diamond ceramics (sp<NUM>-sp<NUM> carbon ceramics), graphitic-doped diamond or Q-carbon family ceramics (sp<NUM>-sp<NUM> carbon ceramics), and/or tri-hybrid-orbital-carbon ceramics (sp<NUM>-sp<NUM>-sp<NUM> carbon ceramics).

Further, the teachings of this disclosure recognize that a negative electron affinity nanoparticle and halogenated solution may be used to 3D print a final ceramic, without the need to form a greenware intermediary that requires heating with a kiln. In addition, the teachings of this disclosure recognize that use of a negative electron affinity nanoparticle may act as a pseudocatalyst that is incorporated into the final ceramic, without the need for using a catalyst or binder that would need to be recovered or extracted after the 3D printing is complete. The following describes methods and systems of 3D printing using a negative electron affinity nanoparticle with a halogenated solution.

The system will be described in more detail using <FIG>. <FIG> will describe an example of a 3D printer system <NUM>, according to certain embodiments. <FIG> will describe the chemical structure of an example negative electron affinity nanoparticle, adamantane diamondoid <NUM>, according to certain embodiments. <FIG> will describe the chemical structure of an example halogenated solution, carbon tetrachloride <NUM>, according to certain embodiments. <FIG> will describe an example ceramic product, polycrystalline diamond, according to certain embodiments. <FIG> will describe a method of additive manufacture of a ceramic using a negative electron affinity nanoparticle with a halogenated solution, according to certain embodiments. <FIG> will describe an example computer system that may be used to control the 3D printer of <FIG>, according to certain embodiments.

<FIG> illustrates an example 3D printer system <NUM>. 3D printer system <NUM> includes 3D printer <NUM> and laser <NUM>. 3D printer <NUM> includes platen <NUM> and enclosure <NUM>. Platen <NUM> is a plate of inert material. For example, platen <NUM> may include platinum. Layers of feedstock <NUM> may be deposited onto platen <NUM> without reacting with platen <NUM>. Feedstock <NUM> includes a negative electron affinity nanoparticle, such as adamantane diamondoid <NUM>, and a halogenated solution, such as carbon tetrachloride <NUM>. Enclosure <NUM> surrounds platen <NUM> and encloses an inert atmosphere <NUM>. Examples of inert atmosphere <NUM> include nitrogen or argon gas. Enclosure <NUM> may maintain an inert 3D printing environment.

Laser <NUM> is configured to raster scan feedstock <NUM> deposited on platen <NUM> to induce solvated electrons from the negative electron affinity nanoparticle, such as adamantane diamondoid <NUM>. Laser <NUM> may emit wavelengths in the UV range. Laser <NUM> may also emit wavelengths in the visible light range. Laser <NUM> may induce a negative electron affinity nanoparticle in feedstock <NUM> to emit electrons into the halogenated solution, such as carbon tetrachloride <NUM>. The electrons may reduce the halogen solution of feedstock <NUM> to form a diatomic halogen gas or liquid and an atom, such as a carbon atom. The carbon atom may nucleate into a ceramic, such as a diamond. Laser <NUM> may be set to certain wavelength or wavelength range. For example, laser <NUM> may be set to a wavelength between <NUM> to <NUM>. As another example, laser <NUM> may be set to a wavelength of <NUM>. The wavelength or wavelength range may be the wavelength necessary to stimulate the emission of electrons from the negative electron affinity nanoparticle.

In some embodiments, 3D printer system <NUM> may include a control unit <NUM>. Control unit <NUM> may include a computer system that controls the printing of an object by providing instructions to 3D printer <NUM>. Control unit <NUM> may be either external to 3D printer <NUM> or incorporated into 3D printer <NUM>. Certain embodiments of control unit <NUM> are discussed in more detail below with respect to FIGURE <NUM>.

In some embodiments, 3D printer system <NUM> may include a flushing mechanism <NUM> configured to flush inert atmosphere <NUM> in enclosure <NUM> and to recover byproduct released into enclosure <NUM>. For example, in some embodiments a halogen gas byproduct may be released into enclosure <NUM>. Flushing mechanism <NUM> may flush the halogen gas byproduct from inert atmosphere <NUM> of enclosure <NUM> and securely store the halogen gas byproduct. In this way, flushing mechanism <NUM> may ensure the halogen gas byproduct does not contaminate inert atmosphere <NUM>. In this way, flushing mechanism <NUM> may also ensure the halogen gas byproduct is not released from 3D printing system <NUM> into the outside atmosphere.

Flushing mechanism <NUM> may use any conventional method of flushing necessary to remove halogen gas from enclosure <NUM> in a way that prevents release of halogen gas into the outside atmosphere. For example, flushing mechanism <NUM> may involve a continuous flow of argon gas through enclosure <NUM> and then through any conventional mechanism for recovering of halogen gas, such as by use of filters or compressors.

In some embodiments, 3D printer system <NUM> may include a draining mechanism <NUM> configured to drain feedstock <NUM>. For example, when 3D printing of an object is complete, there may be leftover feedstock <NUM> on platen <NUM>. Draining mechanism <NUM> may drain the leftover feedstock <NUM> on platen <NUM> into a storage tank. Draining mechanism <NUM> may use any conventional method of draining necessary to remove feedstock <NUM> from platen <NUM>.

Feedstock <NUM> includes a halogenated solution, such as carbon tetrachloride <NUM>. The halogenated solution, for example, may include bromine or chlorine as the halogen. It may be desirable to use a halogenated solution that is liquid at room temperature or at the temperature of the additive manufacture. For example, in embodiments forming a polycrystalline diamond ceramic, carbon tetrachloride or carbon tetrabromide may be liquid at room temperature. Other considerations in selecting a halogenated solution may also include the ease with which the diatomic halogen byproduct may be recovered. In some embodiments, it may be desirable for the other atoms of the halogenated solution to correspond with the atoms making up the ceramic product. For example, a halocarbon may be desirable as the halogenated solution when forming a polycrystalline diamond ceramic.

In embodiments forming a polycrystalline diamond ceramic, any halocarbon may be used as the halogenated solution. In such embodiments, carbon tetrachloride <NUM>, as illustrated in <FIG> may be used. As another example, in such embodiments, carbon tetrabromide may be used in the halogenated solution. In other embodiments forming boron-nitride ceramics, (dichloroamine)dichloroborane (NCl<NUM>-BCl<NUM>) may be used as the halogenated solution and nanoparticle boron nitride as the negative electron affinity nanoparticle.

In yet other embodiments forming a metal carbide ceramic, a metal or semi-metal halogen may be added to carbon tetrachloride <NUM>. For example, in embodiments forming a silicon carbide ceramic, a halogenated solution containing carbon and silicon, such as trimethyltrichlorosilane (i.e., CCl<NUM>Si), may be used. In embodiments forming a silicon carbide ceramic, the halogenated solution may include carbon tetrachloride <NUM> with the addition of silicon tetrachloride (i.e., SiCl<NUM>). In embodiments forming a titanium carbide ceramic, the halogenated solution may include carbon tetrachloride <NUM> and titanium tetrachloride (i.e., TiCl<NUM>). In embodiments forming a hafnium carbide ceramic, the halogenated solution may include carbon tetrachloride <NUM> and hafnium tetrachloride (i.e., HfCl<NUM>). In embodiments forming vanadium carbide, the halogenated solution may include carbon tetrachloride <NUM> and vanadium tetrachloride (i.e., VCl<NUM>). In embodiments forming a tungsten carbide ceramic, the halogenated solution may include carbon tetrachloride <NUM> and tungsten hexachloride (i.e., WCl<NUM>).

In yet other embodiments forming mixed hybrid orbital carbon ceramics, the halogenated solution may include two or more of an sp<NUM> carbon contributor, an sp<NUM> carbon contributor, and an sp<NUM> carbon contributor. For example, in embodiments forming an sp<NUM>-sp<NUM> carbon such as ceramic carbyne-doped diamond ceramic, the halogenated solution may include carbon tetrachloride <NUM> as the sp<NUM> contributor, and dichloroacetylene (i.e., C<NUM>Cl<NUM>) as the sp<NUM> contributor. As another example, in embodiments forming sp<NUM>-sp<NUM> carbon ceramic such as graphitic-doped diamond (Q-carbon family), the halogenated solution may include carbon tetrachloride <NUM> as the sp<NUM> contributor, and tetrachloroethylene (i.e., C<NUM>Cl<NUM>) as the sp<NUM> contributor. The halogenated solution may also include all three of an sp<NUM>, sp<NUM>, and sp<NUM> contributor to form a tri-hybrid-orbital-carbon ceramic.

Feedstock <NUM> also includes a negative electron affinity nanoparticle. Any negative electron affinity nanoparticle suitable to produce solvated electrons when induced by a laser, such as laser <NUM>, may be used depending on the desired ceramic product. The negative electron affinity nanoparticle may act as a pseudocatalyst to produce electrons and nucleate into the ceramic.

In embodiments forming a polycrystalline diamond ceramic, any diamondoid or hydrogen-terminated nanodiamond may be used as the negative electron affinity nanoparticle of feedstock <NUM>. For example in such embodiments, adamantane diamondoid <NUM> as illustrated in <FIG> may be used. Other examples of negative electron affinity nanoparticles that may be used in forming polycrystalline diamond ceramic include diamantane and tetramantane. The nanodiamond or diamondoid emits electrons when illuminated by a laser, such as laser <NUM>. The reduced halocarbon then nucleates on the nanodiamond or diamondoid to form diamond in sp<NUM> form. In this way, polycrystalline diamond ceramic is formed without the intermediary greenware, and without the need to heat an intermediary greenware in a kiln to form a final ceramic.

In embodiments forming a silicon carbide ceramic, an example negative electron affinity nanoparticle may include hydrogen-terminated silicon carbide nanoparticle. In yet other embodiments forming a boron nitride ceramic, negative electron affinity boron-nitride nanoparticles may be used.

<FIG> illustrates the chemical structure of adamantane diamondoid <NUM> (i.e., C<NUM>H<NUM>), which may be used as a negative electron affinity nanoparticle of feedstock <NUM> in certain embodiments forming a polycrystalline diamond.

<FIG> illustrates the chemical structure of carbon tetrachloride <NUM> (i.e., CCl<NUM>), which may be used as a halogenated solution, according to certain embodiments.

<FIG> illustrates the chemical structure of a polycrystalline diamond (i.e., C<NUM>), according to certain embodiments. Polycrystalline diamond is an example of a ceramic formed in certain embodiments. In other embodiments, silicon carbide ceramic may be formed. In yet other embodiments, a mixed carbon hybrid orbital ceramic may be formed.

<FIG> illustrates a method <NUM> for additive manufacture using a negative electron affinity nanoparticle and a halogenated solution. Method <NUM> may be implemented by 3D printer <NUM>. Method <NUM> begins at step <NUM> where a film of feedstock <NUM> is deposited onto platen <NUM> of 3D printer <NUM>. Feedstock <NUM> comprises a halogenated solution and a nanoparticle having a negative electron affinity.

At step <NUM>, laser such as laser <NUM> induces the nanoparticle to emit solvated electrons into the halogenated solution to form layers of a ceramic. The laser inducing the nanoparticle to emit solvated electrons into the halogenated solution also forms a diatomic halogen.

At step <NUM>, if all layers of ceramic needed to form an object have not been deposited, then 3D printer <NUM> will select the next cross section to be printed, and move back to step <NUM>, where a new layer of film is deposited. At step <NUM>, the laser induces the nanoparticle to emit solvated electrons into the halogenated solution to form the next layer of the ceramic.

At step <NUM>, when all layers of the ceramic needed to form the object have been printed, method <NUM> no longer proceeds back to step <NUM>. In some embodiments excess feedstock <NUM> may be drained from the platen, such as platen <NUM>, and into a storage tank or into a disposal tank.

After printing, the object may be subjected to additional processing steps to prepare the object for use. Examples of post-printing processing may include: painting the object, polishing the object, treating the surface of the object to render it chemically inert or to make it chemically active, and assembly of another object or device from multiple printed objects.

Modifications, additions, or omissions may be made to method <NUM> depicted in <FIG>. Method <NUM> may include more, fewer, or other steps. For example, steps may be performed in parallel or in any suitable order. While discussed as various components of system <NUM> performing the steps, any suitable component or combination of components of system <NUM> may perform one or more steps of the method.

<FIG> illustrates an example computer system <NUM> that may be used by the system of <FIG>, according to certain embodiments. One or more computer systems <NUM> perform one or more steps of one or more methods described or illustrated herein. In particular embodiments, one or more computer systems <NUM> provide functionality described or illustrated herein. In particular embodiments, software running on one or more computer systems <NUM> performs one or more steps of one or more methods described or illustrated herein or provides functionality described or illustrated herein. Particular embodiments include one or more portions of one or more computer systems <NUM>. Herein, reference to a computer system may encompass a computing device, and vice versa, where appropriate. Moreover, reference to a computer system may encompass one or more computer systems, where appropriate.

As example and not by way of limitation, computer system <NUM> may be an embedded computer system, a system-on-chip (SOC), a single-board computer system (SBC) (such as, for example, a computer-on-module (COM) or system-on-module (SOM)), a desktop computer system, a laptop or notebook computer system, an interactive kiosk, a mainframe, a mesh of computer systems, a mobile telephone, a personal digital assistant (PDA), a server, a tablet computer system, or a combination of two or more of these.

In particular embodiments, processor <NUM> includes hardware for executing instructions, such as those making up a computer program. As an example and not by way of limitation, to execute instructions, processor <NUM> may retrieve (or fetch) the instructions from an internal register, an internal cache, memory <NUM>, or storage <NUM>; decode and execute them; and then write one or more results to an internal register, an internal cache, memory <NUM>, or storage <NUM>. In particular embodiments, processor <NUM> may include one or more internal caches for data, instructions, or addresses. This disclosure contemplates processor <NUM> including any suitable number of any suitable internal caches, where appropriate. As an example and not by way of limitation, processor <NUM> may include one or more instruction caches, one or more data caches, and one or more translation lookaside buffers (TLBs). Instructions in the instruction caches may be copies of instructions in memory <NUM> or storage <NUM>, and the instruction caches may speed up retrieval of those instructions by processor <NUM>. Data in the data caches may be copies of data in memory <NUM> or storage <NUM> for instructions executing at processor <NUM> to operate on; the results of previous instructions executed at processor <NUM> for access by subsequent instructions executing at processor <NUM> or for writing to memory <NUM> or storage <NUM>; or other suitable data. The data caches may speed up read or write operations by processor <NUM>. The TLBs may speed up virtual-address translation for processor <NUM>. In particular embodiments, processor <NUM> may include one or more internal registers for data, instructions, or addresses. This disclosure contemplates processor <NUM> including any suitable number of any suitable internal registers, where appropriate. Where appropriate, processor <NUM> may include one or more arithmetic logic units (ALUs); be a multi-core processor; or include one or more processors <NUM>. Although this disclosure describes and illustrates a particular processor, this disclosure contemplates any suitable processor.

In particular embodiments, memory <NUM> includes main memory for storing instructions for processor <NUM> to execute or data for processor <NUM> to operate on. As an example and not by way of limitation, computer system <NUM> may load instructions from storage <NUM> or another source (such as, for example, another computer system <NUM>) to memory <NUM>. Processor <NUM> may then load the instructions from memory <NUM> to an internal register or internal cache. To execute the instructions, processor <NUM> may retrieve the instructions from the internal register or internal cache and decode them. During or after execution of the instructions, processor <NUM> may write one or more results (which may be intermediate or final results) to the internal register or internal cache. Processor <NUM> may then write one or more of those results to memory <NUM>. In particular embodiments, processor <NUM> executes only instructions in one or more internal registers or internal caches or in memory <NUM> (as opposed to storage <NUM> or elsewhere) and operates only on data in one or more internal registers or internal caches or in memory <NUM> (as opposed to storage <NUM> or elsewhere). One or more memory buses (which may each include an address bus and a data bus) may couple processor <NUM> to memory <NUM>. Bus <NUM> may include one or more memory buses, as described below. In particular embodiments, one or more memory management units (MMUs) reside between processor <NUM> and memory <NUM> and facilitate accesses to memory <NUM> requested by processor <NUM>. In particular embodiments, memory <NUM> includes random access memory (RAM). This RAM may be volatile memory, where appropriate Where appropriate, this RAM may be dynamic RAM (DRAM) or static RAM (SRAM). Moreover, where appropriate, this RAM may be single-ported or multi-ported RAM. This disclosure contemplates any suitable RAM. Memory <NUM> may include one or more memories <NUM>, where appropriate. Although this disclosure describes and illustrates particular memory, this disclosure contemplates any suitable memory.

In particular embodiments, communication interface <NUM> includes hardware, software, or both providing one or more interfaces for communication (such as, for example, packet-based communication) between computer system <NUM> and one or more other computer systems <NUM> or one or more networks. As an example and not by way of limitation, communication interface <NUM> may include a network interface controller (NIC) or network adapter for communicating with an Ethernet or other wire-based network or a wireless NIC (WNIC) or wireless adapter for communicating with a wireless network, such as a WI-FI network. This disclosure contemplates any suitable network and any suitable communication interface <NUM> for it. As an example and not by way of limitation, computer system <NUM> may communicate with an ad hoc network, a personal area network (PAN), a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), or one or more portions of the Internet or a combination of two or more of these. One or more portions of one or more of these networks may be wired or wireless. As an example, computer system <NUM> may communicate with a wireless PAN (WPAN) (such as, for example, a BLUETOOTH WPAN), a WI-FI network, a WI-MAX network, a cellular telephone network (such as, for example, a Global System for Mobile Communications (GSM) network), or other suitable wireless network or a combination of two or more of these. Computer system <NUM> may include any suitable communication interface <NUM> for any of these networks, where appropriate. Communication interface <NUM> may include one or more communication interfaces <NUM>, where appropriate. Although this disclosure describes and illustrates a particular communication interface, this disclosure contemplates any suitable communication interface.

The components of computer system <NUM> may be integrated or separated. In some embodiments, components of computer system <NUM> may each be housed within a single chassis. The operations of computer system <NUM> may be performed by more, fewer, or other components. Additionally, operations of computer system <NUM> may be performed using any suitable logic that may comprise software, hardware, other logic, or any suitable combination of the preceding.

Claim 1:
A method for additive manufacture, comprising:
depositing a film of a feedstock onto a platen of a three-dimensional (3D) printer, wherein the feedstock comprises a solution and a nanoparticle having negative electron affinity;
inducing the nanoparticle to emit solvated electrons into the solution using a laser to form, by reduction, layers of a ceramic and a diatomic halogen;
wherein each layer of the ceramic is formed in a shape corresponding to a cross section of an object;
wherein the film of the feedstock is deposited until the layers of the ceramic form the shape of the object;
wherein the solution is one or more of carbon tetrachloride or carbon tetrabromide; and the ceramic comprises a polycrystalline diamond; or
wherein the solution is (dichloroamine)dichloroborane; and the ceramic comprises boron-nitride ceramic; or
wherein a metal or semi-metal halogen is added to carbon tetrachloride as the solution; when the ceramic is a metal carbide ceramic; wherein, in case of a silicon carbide ceramic, a solution comprising carbon and silicon, such as trimethyltrichlorosilane, is used; in case of a silicon carbide ceramic, a solution comprising carbon tetrachloride and silicon tetrachloride is used; in case of a titanium carbide ceramic, a solution comprising carbon tetrachloride and titanium tetrachloride is used; in case of a hafnium carbide ceramic, a solution comprising carbon tetrachloride and hafnium tetrachloride is used; in case of vanadium carbide, a solution comprising carbon tetrachloride and vanadium tetrachloride is used; and in case of tungsten carbide ceramic, a solution comprising carbon tetrachloride and tungsten hexachloride is used; orwherein the solution comprises carbon tetrachloride as an sp<NUM>-carbon contributor and dichloroacetylene as an sp<NUM>-carbon contributor, and the ceramic comprises a mixed carbon hybrid orbital ceramic; or
wherein the solution comprises tetrachloroethylene as an sp<NUM>-carbon contributor and carbon tetrachloride as an sp<NUM> carbon contributor, and the ceramic comprises a mixed carbon hybrid orbital ceramic; or
wherein the solution is a halogenated silicon-carbon compound, and the nanoparticle is a hydrogen-terminated silicon carbide nanoparticle.