IN THE UNITED STATES PATENT AND TRADEMARK OFFICE

Utility Patent Application (Provisional)

TITLE: NOVEL INVENTION FOR ADDITIVELY MANUFACTURING CONDUCTIVE MATERIAL THROUGH _______________________________ OF THE FILAMENT.

INVENTOR:

MEMBERS:

FIELD OF THE INVENTION

[0001]The claimed invention describes a novel design for a conductive nozzle which could be used in a system to additively manufacture conductive metallic materials through _______________________________. This heating is used to induce a phase transformation in the conductive material near the nozzle outlet, allowing the material to be deposited on a build platform.

BACKGROUND

[0002]Additive Manufacturing (AM) for structural applications is currently a field of interest as it allows complex part geometries and materials which would be unachievable through subtractive manufacturing methods. The use of additive manufacturing in order to quickly 3D print custom designs is valuable in the fields of medicine, energy, and aerospace for rapidly prototyping production parts, manufacturing tooling, and creating complex designs which would be expensive to manufacture in any other way. Currently, machines capable of additively manufacturing metal with accuracy and repeatability are very expensive and deemed generally unattainable by individual inventors or start-ups due to the investment required. To date, the ‘hobbyist’ market has been flooded with budget Fused Deposition Modeling (FDM) and Fused Filament Fabrication (FFF) machines capable of producing polymer parts, but lack the concentrated energy requirements and temperature controls necessary to melt metal. Commercial-grade metal AM processes such as Selective Laser Sintering (SLS), Powder Bed Fusion (PBF), and Direct Metal Laser Sintering (DMLS) exist, all which basically utilize a thermal source for introducing fusion in to a metal powder. Any metal that is fusion weldable is a good candidate for these processes, but are challenged with residual stress build up through uneven heating based in-part on powder quality, and limited by heating rates capable of being produced in the energy source. Other metal AM processes fall into the category of Directed Energy Deposition (DED), which instead directs energy onto material substrate to form a bead which can be deposited, either in the form of a powder or wire. This method typically utilizes a melting process similar to welding, through a laser or electron beam heat source. To date, no process has been developed which utilizes high-current energy, which is enabled through this innovative nozzle design. Additionally, Directed Energy processes to date lack the feature resolution of powder based processes which could be achieved through this process.

[0003]The most common method to create a design out of metal is to machine the design out of a block of metal. The block of metal is then shaved down until the desired design remains from the block of metal. This process is wasteful since the metal shaved from the block is unusable and therefore wasted. The company must also buy more metal in order to compensate for this wasted/unused material. Also, designs created by the machining process is limited. For example, the machining process is not able to create a hollow ball since the machinist must drill into the center of the metal in order to create a hollow design. Another drawback of the machining process is that it is a slow process since the metal must be shaved off of the original metal block until the final design is achieved, so the entire design process is slowed down by the machining process. Machining is a difficult process, and training to become certified to use CNC machines can range from six months to a year.

BRIEF SUMMARY OF THE INVENTION

[0004]The present invention generally consists of a two part extruder that is separated by an insulator, an insulative lining that is present to prevent contact between the metal filament and the two parts of the extruder, and two contact points used to transfer current between the extruding nozzle and the conductive filament. The invention generally works by passing current between the two contacts of the extruder through the conducting wire. As the current is moved between the two electrical contacts, the electrical resistance of the metal filament is used to produce heat. The resultant heat is then used to melt the filament and cause a phase change in the filament from solid to extrudable liquid. Electrical and thermal insulators are present between the filament and the extruder in order to prevent the transfer of and production of heat within the supporting material of the extruder.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005]Some embodiments of the present invention are illustrated as an example and are not limited by the figures of the accompanying drawings, in which like references may indicate similar elements and in which:

[0006]Fig. 1 - Figure 1 depicts a front facing cross-section of the nozzle and shows the pathway of the current.

[0007]Fig. 2 - Figure 2 depicts the top down cross-section of the extruder nozzle.

DETAILED DESCRIPTION OF THE INVENTION

[0008]The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well as the singular forms, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or groups thereof.

[0009]For the course of this provisional patent application, all terms (unless specifically stated otherwise) has the same meaning as commonly understood by one having ordinary skill in the art to which this invention belongs. Furthermore, it should be understood that terms, such as those defined in commonly used dictionaries, should be interpreted in the context of the relevant art and present explanation and should not be idealized or overly formal unless explicitly expressed.

[00010]The present invention utilizes very high currents and low voltages coupled with a novel nozzle design that efficiently transfers power from a power source to a metallic material to melt for additive manufacturing purposes. The fundamental idea behind this design is based on two equations: and . Substituting equation (1) into equation (2) yields . What can be driven from this equation is that current is a major contributor to power. From there one can extrapolate having a low resistance will increase the power because a lower resistance means a higher current and the squared current dominates the resistance. Knowing this metals are a perfect material to print using high current discharging because they have low resistance.

The basic circuit consists of a power source, the total resistance of all current carrying materials excluding the metallic material to melt, and the resistance of the metallic material

[00011]The extruder is a two piece device that surrounds the metallic filament. This system consists of two side wall pieces that serve to support the extruded filament, and to ensure the proper alignment of filament between the two electrical contacts. The extruder sidewalls are made of a metal with a high melting temperature relative to that of the filament, and are separated by the presence of insulative spacers to prevent the walls from being directly electrically or physically connected. Metallic contacts are present in the extruder and pass past the insulative spacing of the extruder.

[00012]The ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ The electrical contacts are made of a metallic material with a high melting point in order to prevent excessive heat within the extruder from melting the contacts themselves. The contacts are supported by the two halves of the extruder, which also serves to ensure that filament is properly aligned and that it makes a connection between the two contacts.

[00013]Between the electrical contacts of the system is a insulative ring which serves to prevent electrical contact between the conductive filament and the sidewalls of the extruder. The insulative ring serves to allow for

CLAIMS

What is claimed is:

1. How the current travels through the wire.

2. Maybe: low voltage high current discharge melting of metallic materials

ABSTRACT:

[00014]The present invention comprises of a novel additive manufacture.

The core of the invention is ________________________________________________________________________________________________________________________________________________________________________________________________________________ This invention is the first sub-$1000 device which could be used standalone or as an addition to existing machines to additively manufacture metals at a low cost.

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