US20220297191A1

US20220297191A1 - System and method for forming material substrate printer

Info

Publication number: US20220297191A1
Application number: US17/744,721
Authority: US
Inventors: James A. DEMUTH; Andrew BAYRAMIAN; Bassem S. EL-DASHER; Kevin J. Kramer
Original assignee: Lawrence Livermore National Security LLC
Current assignee: Lawrence Livermore National Security LLC
Priority date: 2014-10-02
Filing date: 2022-05-15
Publication date: 2022-09-22
Also published as: US20200368817A1; US11446741B2; US10737324B2; US20160096224A1

Abstract

The present disclosure relates to a system for manufacturing a part via an additive manufacturing process. The system uses a reservoir for containing a heated solution forming a mixture of a volatile component and meltable powdered material particles, the heated solution being heated to a point where the heated solution is at least about to begin boiling. A nozzle associated with the reservoir channels a quantity of the heated solution onto at least one of a substrate or a previously formed material layer. A processor controls a flow of the heated solution through the nozzle onto at least one of the substrate or the previously formed material layer. A heat source responsive to the processor generates heat to melt the powdered material particles. The heat source is controlled to melt the powdered material particles after the volatile component has at least substantially evaporated from the mixture. The volatile component cools a previously formed material layer before heating of the powdered material particles takes place, and the heating of the particles fuses the particles into a single structural layer, thus forming the part exclusively from the particles.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional and claims priority of U.S. patent application Ser. No. 16/989,463, filed Aug. 10, 2020 and presently allowed, which in turn claims priority from U.S. patent application Ser. No. 14/504,646 filed on Oct. 2, 2014. The entire disclosure of each of the above applications is incorporated herein by reference.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with Government support under Contract No. DE-AC52-07NA27344 awarded by the United States Department of Energy. The Government has certain rights in the invention.

FIELD

The present disclosure relates to additive manufacturing systems and processes, and more particularly to an additive manufacturing system and method which delivers a powdered material suspended in a solution to a surface, after which the solution evaporates leaving just the powdered material, which is then melted by a heat source to form a material layer of a part.

BACKGROUND

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Current powder delivery systems for additive manufacturing (“AM”) processes such as Selective Laser Sintering (“SLS”), Direct Metal Laser Sintering (“DMLS”), or Diode based Additive Manufacturing use a single type or composition of powder per part. The powder is swept over a lowered part creation zone creating a layer of powder of a specified thickness.
As layer upon layer of material is deposited in a traditional SLS or DMLS system, the part being created grows thicker and thicker. For the first few initial layers of part creation, the heat delivered to melt the material is removed by conduction to the base substrate that the powder is initially deposited on. As the part becomes thicker and thicker, this conduction pathway becomes insufficient at removing the excess heat in the part. As a result, the part begins to rise in temperature. The temperature of the part continues to increase as successive materials layers are melted, until the part eventually reaches a temperature which is just below the melting point of the powder. Accordingly, cooling the part to permit the continued application of material layers typically becomes a significant challenge. Complicating this is the desire to be able to fully complete the manufacture of the part, using the AM manufacturing process, in as short a time as possible.
Also, in traditional SLS or DMLS systems, the powder bed is filled with the powder to be melted, as well as a portion of the powder which is not melted. This can result in the powder bed being required to support significant weight when heavy and/or dense powdered material types are being used.

SUMMARY

The present disclosure relates to a system for manufacturing a part via an additive manufacturing process. The system may comprise a reservoir for containing a heated solution forming a mixture of a volatile component and meltable powdered material particles, the heated solution being heated to a point where the heated solution is at least about to begin boiling. A nozzle is included which is operably associated with the reservoir for channeling a quantity of the heated solution onto at least one of a substrate or a previously formed material layer. A processor is included which is configured to control flow of the heated solution through the nozzle to enable the heated solution to be flowed onto at least one of the substrate or the previously formed material layer. A heat source is included which is responsive to the processor for generating heat sufficient to melt the meltable powdered material particles. The heat source is controlled to melt the meltable powdered material particles in the quantity of the heated solution flowed onto at least one of the substrate or a previously formed material layer after the volatile component has at least substantially evaporated from the mixture. The volatile component operates to cool a previously formed material layer before heating of the meltable powdered material particles takes place, and wherein the heating of the meltable powdered material particles fuses the meltable powdered material particles into a single structural layer. The part is thus formed exclusively by the meltable powdered material particles.
In another aspect the present disclosure relates to a system for manufacturing a part via an additive manufacturing process. The system may comprise a reservoir for containing a heated solution forming a mixture of a volatile component and meltable powdered material particles, the heated solution being heated to a point where the heated solution is at least about to begin boiling. A nozzle is included which is operably associated with the reservoir for channeling a quantity of the heated solution onto at least one of a substrate or a previously formed material layer. A processor is included which is configured to control flow of the heated solution through the nozzle to enable the heated solution to be flowed onto at least one of the substrate or the previously formed material layer. A heat source is included which is responsive to the processor for generating heat sufficient to melt the meltable powdered material particles. The heat source is controlled to melt the meltable powdered material particles in the quantity of the heated solution flowed onto at least one of the substrate or a previously formed material layer after an expiration of a predetermined time period sufficient to enable the volatile component to be at least substantially evaporated from the mixture. The volatile component provides a cooling effect on a previously deposited material layer of a part being formed in a layer by layer process, and such that the cooling takes place intermittently with every application of a new quantity of the meltable powdered material particles about to be fused to form a new structural layer of the structural part. The heating of the meltable powdered material particles fuses the meltable powdered material particles, layer by layer, into a single structural layer, and the part is formed exclusively by the meltable powdered material particles.
In still another aspect the present disclosure relates to a system for manufacturing a part via an additive manufacturing process. The system comprises a first reservoir for containing a first heated solution forming a mixture of a first volatile component and a quantity of first meltable powdered material particles. The system also comprises a first nozzle operably associated with the first reservoir for channeling a quantity of the heated solution onto at least one of a substrate or a previously formed material layer. A second reservoir is included for containing a second heated solution forming a second mixture of a second volatile component and a quantity of second meltable powdered material particles. A second nozzle is included which is operably associated with the second reservoir to channeling a quantity of the second heated solution onto at least one of the substrate or the previously formed material layer. A processor is included which is configured to control flow of the flows of the first heated solution through the first nozzle and the second heated solution through the second nozzle, to enable the first and second heated solutions to be flowed onto at least one of the substrate or the previously formed material layer. A laser is included which is configured to produce an optical signal. The laser is responsive to the processor and the optical signal generates heat sufficient to melt the quantities of first and second meltable powdered material particles. The laser is controlled to melt the quantities of first and second meltable powdered material particles in the first and second heated solutions flowed onto at least one of the substrate or a previously formed material layer after an expiration of a predetermined time period sufficient to enable the volatile components in the quantities of first and second heated solutions to be at least substantially evaporated. The volatile component of each of the first and second heated solutions provides a cooling effect on a previously deposited material layer of a part being formed in a layer by layer process, and such that the cooling takes place intermittently with every application of a new quantity of the first meltable powdered material particles and the second meltable powdered material particles about to be fused to form a new structural layer of the structural part. The heating of the meltable powdered material particles fuses the meltable powdered material particles, layer by layer, into a single structural layer, and the part is formed exclusively by the meltable powdered material particles.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

FIG. 1 is a high level illustration of a system in accordance with one embodiment of the present disclosure; and

FIG. 2 is a flowchart illustrating one example of operations that may be performed by the system of FIG. 1 in carrying out an Additive Manufacturing (“AM”) process to manufacture a part.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
The system and method of the present disclosure makes use of a cooling mechanism in the form of a volatile solvent. The volatile solvent acts as a carrier fluid for material particles which are deposited on a substrate, or on a previously formed layer, during an additive manufacturing (“AM”) process. The latent heat of vaporization of the fluid is capable of removing a great deal of heat and can effectively cool the surface of the part where it sees the thermal heat flux, and is the hottest.
Referring to FIG. 1, a system 10 in accordance with one embodiment of the present disclosure is illustrated. The system 10 may include one or more material deposition components, in this example nozzles 12-16, that are each able to deposit an associated solution 12 a-16 a which includes particles, for example metallic particles, that will be melted to form successive material layers one on top of another. In this example the solutions 12 a-16 a each include different types of particles 22 a-22 c, respectively. As a result, a part made using the system 10 may be formed from a plurality of different types of materials. This is in contrast to traditional types of AM systems which are only able to make a part using a single type of material.
While three nozzles 12-16 are illustrated, the system 10 is not limited to use with any particular number of different nozzles or material types. Thus, it is expected that the desired material qualities and/or the specific type of part being manufactured may dictate whether one, two, three or more different material types will be chosen/required for making a specific part.
Each of the nozzles 12-16 includes an associated reservoir R1, R2 and R3, where a specific solution is contained that is deposited through its associated nozzle 12-16. Operation of the deposition of the solution from each nozzle 12-16 may be controlled by a processor 18 by opening and closing suitable valves V1, V2 and V3 associated with the nozzles 12-16. The processor 18 may also control a suitable heat source 20 for melting the particles of powdered material 22 a-22 c in each of the solutions 12 a-16 a after each is deposited on a substrate. The heat source 20 may comprise any device suitable for providing the required heat to melt the particles 22 a-22 c. For example, the heat source 20 may be formed by a laser or a diode laser light source. A high powered diode laser system that may be suitable for use in forming the system 10 is disclosed in co-pending U.S. patent application Ser. No. 13/785,484, filed Mar. 5, 2013 (U.S. Pub. No. 2014/0252687), and assigned to Lawrence Livermore Security LLC, the teachings of which are hereby incorporated by reference into the present disclosure.
The processor 18 may include suitable software 18 a which includes information stored in a non-volatile memory, for example a lookup table 18 c stored in non-volatile random access memory 18 b, on specific temperatures and/or durations that need to be delivered to melt the particles of powdered material 22 a-22 c in each solution 12 a-16 a. As such, the delivery of optical power can be specifically “tuned” to the specific types of particles mixed into each of the solutions 12 a-16 a in order to melt the different types of particles within a determined time frame. The solutions 12 a-16 a in FIG. 1 may have the particles of powdered material 22 a, 22 b and 22 c, respectively, suspended in volatile components 24 a, 24 b and 24 c, respectively. The volatile components 24 a-24 c each act as a carrier fluid. The volatile components 24 a-24 c may comprise, for example, methanol, ethanol, acetone or any other suitable fluid capable of using latent heat of vaporization for cooling purposes.
Each solution 12 a-12 c is applied to a substrate 26 (or to a previously formed material layer) while the solution 24 a-24 c is at, or nearly at, its boiling point. As a result of the latent heat of vaporization, the volatile component 24 a-24 c of each solution 12 a-12 c then evaporates, leaving just the previously suspended particles of powdered material 22 a-22 b on the substrate 26 (or previously formed material layer) in the desired configuration. Importantly, the latent heat of evaporation effectively helps to cool the surface, that is either the substrate 26 or the surface of the previously formed layer(s), in the process.
Similar to how an inkjet printer delivers multi-colored ink, the system 10 is able to deliver multiple types of powdered materials. The powder layer remaining after the volatile component 24 a-24 c of each solution 12 a-12 c evaporates may be melted with the heat source 20 using a predetermined amount of energy selected for the specific type of powdered material. Thus, different types of particles of powdered material may have different amounts/levels of heat used to accomplish the melting of the particles thereof. The next layer of solution 12 a-12 c can then be deposited onto the surface of the just-formed layer and the material powder 22 a-22 b subsequently melted using the heat source 20. The evaporative cooling caused by the latent heat of vaporization of the volatile component 24 a-24 c of each solution 12 a-12 c keeps the surface of the previously formed material layer, and thus the part that is being produced, at a relatively constant temperature. This is an important benefit because it helps to maintain the entire part at an acceptable temperature as one layer after another of the part is built up using the system 10. As AM processes increase in speed in the years to come, the waste process heat might be such that the manufacturing process will need to periodically stop to give the part time to cool down. This technique would eliminate that need.
A particularly significant advantage of the system 10 is that it enables the manufacturing of parts containing many different materials to be fabricated in a single layer at once, or substantially at once. Thus, as an example, portions of a part that may require additional strength may be formed from one or more types of powdered material while other portions of the part requiring less strength can be formed using different types of powdered material. The ability to form a single part from a plurality of different powdered materials, and to be able to control where each powdered material is deposited, enables the physical properties of the produced part to be closely tailored to meet specific performance requirements (e.g., durability, longevity, thermal tolerance, stress tolerance, etc.) for the produced part.
The system 10 also enables potentially faster powder deposition over traditional “sweeping” methods typically employed in an AM process. In such traditional methods, typically one raster scan of material is laid down, with a plurality of scans (sometimes dozens or even hundreds) being required to form a single material layer. The system 10 enables multiple materials to be “printed” simultaneously, or virtually simultaneously, using the heat source 20 to form an entire layer of the part at one time or substantially at one time. The ability to cool the underlying surface on which the newest layer of solution 12 a-12 c has been applied, using the evaporative cooling which results from the latent heat of vaporization of the volatile components 24 a-24 c, allows cooling to be achieved at those locations on the part where the cooling is needed the most.
While a bed of powder may still be necessary for support, the bed can be made of materials that are of low cost while high cost materials can still be used in the layer that form portions of the actual part being produced. This eliminates the need to have a powder bed full of the material that is to be printed, especially if the printed part is small relative to the bed size, the material to be printed is expensive, or of high density. The nozzles 12 a-12 c can be rastered across the powder bed using the processor 18, printing (i.e., depositing) either only where material is desired, or printing material where desired to melt, and using a less expensive or lighter weight filler material everywhere else. In this regard it will be appreciated that by being able to use different types of powdered materials, the system 10 may potentially enable a part to be produced which is lighter than what would otherwise be the case with an AM formed part made from a single material.
Referring to FIG. 2, a flowchart 100 is presented that provides one example of various operations that may be carried out in implementing the system 10 to make a specific part. At operation 102 the material reservoir(s) are each loaded with the different types of solutions that have been selected to make the part. For this example, it will be assumed that a plurality of different solutions 12 a-12 c are being used, with each solution containing a different type of powdered material 22 a-22 c and a specific volatile component 24 a-24 c, which may be the same or which may differ from one another. At operation 104 the processor 18 may be used to control movement of the nozzles 12-16 to deposit the solutions 12 a-16 a at specific locations on the substrate 26 while the volatile components 24 a-24 c of each of the solutions 12 a-16 a are at or near their respective boiling points. The volatile component 24 a-24 c of each solution 12 a-16 a will evaporate very rapidly after the solutions 12 a-16 a are deposited on the substrate 26, typically within a few seconds or less, thus leaving only the powdered materials 22 a-22 c.
At operation 106 the heat source 20 may then be used to melt the powdered materials 22 a-22 c. The melting may be performed across the entire material layer substantially at once, rather than by raster scanning the heat source 20 back and forth over the substrate 26. This significantly expedites the formation of each layer of the part. As the melting of the powdered materials 22 a-22 c occurs, the particles of each type of material are fused together. Thus, any portions where powdered materials 22 a remain will be fused into a solid section of the material layer, and the same will occur for powdered materials 22 b and 22 c.
At operation 108, a check is made by the processor 18 if the entire part has been completed, and if not, then operations 104-108 are re-performed as many times as needed to form the entire part, layer by layer. Once the check at operation 108 indicates that the part is completely formed, the AM process is then complete.
The system 10 and method thus allows for a plurality of powdered materials to be deposited, simultaneously, at each layer of a part to tailor the use of materials to the physical characteristics that are needed for the part. The latent heat of vaporization of the fluid also enables the part to be maintained at a reasonably consistent temperature during the AM process, which would otherwise be difficult or impossible to achieve with a conventional AM process.
While various embodiments have been described, those skilled in the art will recognize modifications or variations which might be made without departing from the present disclosure. The examples illustrate the various embodiments and are not intended to limit the present disclosure. Therefore, the description and claims should be interpreted liberally with only such limitation as is necessary in view of the pertinent prior art.

Claims

1. A system for manufacturing a part via an additive manufacturing process, the system comprising:

a reservoir for containing a heated solution forming a mixture of a volatile component and meltable powdered material particles, the heated solution being heated to a point where the heated solution is at least about to begin boiling;

a nozzle operably associated with the reservoir for channeling a quantity of the heated solution onto at least one of a substrate or a previously formed material layer;

a processor configured to control flow of the heated solution through the nozzle to enable the heated solution to be flowed onto at least one of the substrate or the previously formed material layer;

a heat source responsive to the processor for generating heat sufficient to melt the meltable powdered material particles;

wherein the heat source is controlled to melt the meltable powdered material particles in the quantity of the heated solution flowed onto at least one of the substrate or a previously formed material layer after the volatile component has at least substantially evaporated from the mixture, the volatile component operating to cool a previously formed material layer before heating of the meltable powdered material particles takes place, and wherein the heating of the meltable powdered material particles fuses the meltable powdered material particles into a single structural layer; and

wherein the part is formed exclusively by the meltable powdered material particles.

2. The system of claim 1, wherein the processor is configured to alternately apply a quantity of the heated solution and then to cause the heat source to heat the quantity of the heated solution, in repeated fashion, to form multiple layers of the part in a layer by layer fashion, wherein the multiple layers are fused to one another.

3. The system of claim 1, wherein the volatile component comprises at least one of methanol, acetone or ethanol.

4. The system of claim 1, further comprising an additional reservoir for holding an additional heated solution different from the heated solution, and wherein quantities of the additional heated solution are deposited by the processor and heated using the heat source to help.

5. The system of claim 1, further comprising an additional reservoir including a different heated solution.

6. The system of claim 5, wherein the different heated solution includes the meltable powdered material particles.

7. The system of claim 5, wherein the different heated solution includes different meltable powdered material particles.

8. The system of claim 7, wherein the processor is further configured to control the heat source to tailor an application of heat to the different meltable powdered material particles to achieve melting of the different meltable powdered material particles.

9. The system of claim 1, wherein the heat source comprises a laser.

10. The system of claim 9, wherein the laser comprises a diode laser.

11. The system of claim 1, further including a memory for storing a look-up table, the look-up table including at least one of times or temperatures that need to be used to melt the meltable powdered material particles.

12. A system for manufacturing a part via an additive manufacturing process, the system comprising:

a heat source responsive to the processor for generating heat sufficient to melt the meltable powdered material particles; and

wherein the heat source is controlled to melt the meltable powdered material particles in the quantity of the heated solution flowed onto at least one of the substrate or a previously formed material layer after an expiration of a predetermined time period sufficient to enable the volatile component to be at least substantially evaporated from the mixture, the volatile component providing a cooling effect on a previously deposited material layer of a part being formed in a layer by layer process, and such that the cooling takes place intermittently with every application of a new quantity of the meltable powdered material particles about to be fused to form a new structural layer of the part; and

wherein the heating of the meltable powdered material particles fuses the meltable powdered material particles, layer by layer, into a single structural layer; and

13. The system of claim 11, wherein the volatile component comprises at least one of methanol, acetone or ethanol.

14. The system of claim 11, wherein the heat source is controlled to melt an entire layer of the meltable powdered material particles at once.

15. The system of claim 11, wherein the heat source comprises a laser.

16. The system of claim 15, wherein the laser comprises a diode laser.

17. The system of claim 11, further comprising an additional reservoir for containing an additional heated solution containing an additional quantity of meltable powdered material particles.

18. The system of claim 17, further comprising a first nozzle associated with the reservoir, and a second nozzle associated with the additional reservoir; and

wherein the processor is configured to control the first and second nozzles to control an application of the heated solution and the additional heated solution during manufacture of the part.

19. The system of claim 18, wherein at least one of:

the heated solution differs from the additional heated solution; or

the quantity of meltable powdered material particles differs from the additional quantity of meltable powdered material particles.

20. A system for manufacturing a part via an additive manufacturing process, the system comprising:

a first reservoir for containing a first heated solution forming a mixture of a first volatile component and a quantity of first meltable powdered material particles;

a first nozzle operably associated with the first reservoir for channeling a quantity of the heated solution onto at least one of a substrate or a previously formed material layer;

a second reservoir for containing a second heated solution forming a second mixture of a second volatile component and a quantity of second meltable powdered material particles;

a second nozzle operably associated with the second reservoir to channeling a quantity of the second heated solution onto at least one of the substrate or the previously formed material layer;

a processor configured to control flow of the flows of the first heated solution through the first nozzle and the second heated solution through the second nozzle, to enable the first and second heated solutions to be flowed onto at least one of the substrate or the previously formed material layer;

a laser configured to produce an optical signal, the laser being responsive to the processor and using the optical signal to generate heat sufficient to melt the quantities of first and second meltable powdered material particles;

wherein the laser is controlled to melt the quantities of first and second meltable powdered material particles in the first and second heated solutions flowed onto at least one of the substrate or a previously formed material layer after an expiration of a predetermined time period sufficient to enable the volatile components in the quantities of first and second heated solutions to be at least substantially evaporated, the volatile component of each of the first and second heated solutions providing a cooling effect on a previously deposited material layer of a part being formed in a layer by layer process, and such that the cooling takes place intermittently with every application of a new quantity of the first meltable powdered materials and the second meltable powdered material particles about to be fused to form a new structural layer of the structural part; and

wherein the heating of the first and second meltable powdered material particles fuses the first and second meltable powdered material particles, layer by layer, into a single structural layer; and

wherein the part is formed exclusively by the first and second meltable powdered material particles.