3D_Metal_Printer_Specifications.docx

12 Feb16

Specifications for Metal Fusing Machine

1. NRL is seeking to purchase an off-the-shelf multi-laser metal fusing machine (in other words, a 3D metal printer) that is available to the public at large. We do NOT want a prototype system or anything that is one-of-a-kind or limited run, but rather are seeking a system that is widely available to the public, and that has been manufactured by a company that has a clear and demonstrable track record of selling and supporting many such machines. The system will be used as a tool to perform basic scientific research: it will be used to fabricate innovative devices to further NRL's scientific research at the cutting edge of the physical sciences.

a. The system must be manufactured by an established company with a proven track record of manufacturing and supporting the system we currently seek. Their normal business operations must include routine selling and support of such machines, and they should be able to provide at least a dozen references for current clients who can support the veracity of their claims for machine performance and operation. It should also be a company whose reputation is well known to experts in the field, who can and could also offer unbiased testimony regarding all aspects of the system we seek, including performance, reliability, support and longer-term operational pitfalls.

b. There must be a reasonable expectation of support and replacement parts being available for the system for the foreseeable future.

c. NRL does NOT want a prototype machine, a custom-built machine, or a machine of limited run. Rather, it should be a machine that has been available to the public at large as an off-the-shelf system, continues to be available, and will be available for the foreseeable future.

2. NRL requires an integrated system of seamlessly interoperating parts (henceforth referred to as "The Machine" or "The System") for handling both reactive and non-reactive media. The programming interface must be of a modern design, and must be demonstrable to NRL scientists. There is an expectation that it will be clear and understandable to NRL scientists after initial training: Training must also be available either on site at N R L or at an established company training venue, at a selection of times mutually suitable to both the company and NRL scientists.

3. A powerful, modern, multi-core processing computer must control the machine: This should be at least equivalent to an Intel Core i7 Quad core running at 2.3 GHz, with 16G B of RAM, at least O.STB of SSD storage, and running a 64-bit Windows 10 operating system. The machine must employ "Magics" 3D printing software as the means of handling NRL's models and designs: this software must be integral to the operation of the machine, and operate in a seamless manner. (In other words, it is not acceptable for NRL scientists to have to go through a complicated and/or time consuming process to have the system handle their 30 models.)

4. Installation should be possible by NRL electricians, pipe fitters, and riggers. No additional specialized personnel should be needed. For initial startup, technical support and on-site training (actually on the machine that NRL purchases) from the vendor must be provided at a mutually agreeable time. The manufacturer must provide delivery to NRL, along with complete and detailed documentation for machine installation that can be understood and carried out by NRL support personnel (who are themselves experienced electricians and fitters).

5. Future on-site (NRL) troubleshooting must be available at fairly short notice (days rather than weeks). The supplier must have a demonstrable capability of being able to provide this service. If the machine is provided through a third party (i.e. Not the original manufacturer), all warranties, and support provided by the OEM must be honored, including options for extended periods of performance.

6. The system must comply with relevant electrical, laser and explosive (dusts and powders) safety standards. It is incumbent on the vendor to demonstrate to NRL how their system complies with the highest possible safety standards, and what those safety standards are.

7. Minimum build size shall be :2250 mm (X-axis), :2 250 mm (Y-axis) and :2 280 mm (Z-axis).

8. The machine must be a dual fiber laser system, with each laser having fully overlapping build area (with each capable of exposing the entire build plane). The lasers should each be capable of operating at a maximum power of 400W, and should each be capable of dialing-back the duty cycle to 10% on each laser, independently. (In other words, each laser, independently, must be able to span the range of power from 40W to 400W.) The lasers must be single mode with a Gaussian beam profile. The user must have the capability to assign what task each laser head is performing.

9. Each laser must have its own independent 30 optics system that is capable of scanning each laser beam over the build area and dynamically adjusting its focus.

10. The system must have an integrated through-the-lens capability to monitor the melt-pool size, shape and intensity. A minimum requirement is that the machine must be recording information for every 150-200µm of the weld seam.

11. System shall provide optical access to the build chamber in the form of windows or ports to allow implementation of future process monitoring sensors.

12. The system must be an open architecture whereby NRL can modify the manufacturer’s process para meters in addition to the option of creating an entirely new set of our own choosing. The system should have an advanced process parameter editor providing the user with full control of the processing specifics.

13. The system must accept open source powders: NRL cannot be tied down to a machine that can only use powders from the manufacturer of the machine. This is a research tool, and NRL expects to be experimenting with various materials: as such, the machine operation cannot limit NRL on their source of materials.

14. The recoating system must offer interchangeable blades with a wide variety of properties, ranging from rigid (such as steel) through semi rigid (such as thermoplastics) down to flexible (such as rubber).

15. The ventilator system that keeps the process gas clean while a build is running must include filters with a large area (<::10m 2 for individual filters, with a minim um of ;::20 m 2 total area) to maximize the time between filter changes. The process for filter replacement-should be simple, requiring no more than 5 minutes of an NRL scientists' time once they have been trained. During the filter changes the filters must be fully passivated with water before they are removed from the system: there should be no dust generated in this process, and at no point should the operator be exposed to unpassivated filters.

16. The system must be of a design where it is possible to continuously operate without having to pause the printing process in order to load more media into the system. All ancillary equipment needed for a smooth and uninterrupted operation must be part of the system.

17. Enough 316L stainless steel powder to fully fill the machine one time must be included with the system. A spare set of "wear parts" -parts that are reasonably expected to need replacing in an intermediate time frame -must be included with the system.

18. The machine must have no internal sieves: all sieves must be external and easily accessible for maxim um ease of use during material changes. The machine must be convenient for the scientists to use, and must not present complicated or time consuming procedures related to material handling and changes of materials being used in the system. The machine must be able to change materials in a 3 to 4 hour time interval when being run by a single operator.

19. The machine must have redundant oxygen sensing capability to ensure the safety of the operator and the machine.

20. The system must have a fully nerted set-up/ unpacking area that is separated from the main build chamber, whereby the operator can load powder into the system without it being exposed to oxygen, and without is being contaminated by soot generated in the build chamber. This area should be of an ergonomic design, affording a good amount of space for an NRL scientist to work in.

21. The machine must employ a single-sided powder bed recoating system. As part of the powder batch control, the system must provide a means of keeping track of how many times the powder has been used.

22. Bearings and moving parts exposed to the powder stream is a failure poi nt. NRL favors machine’s whose design minimizes this failure point.

23. The machine must be of an open design in the sense that NRL must be able to add features to the build volume in the future. (For example, NRL might want to add a new camera to monitor the build process.) To facilitate this, the build chamber must have windows/blanks/ports available for future capability.

24. The weld penetration is an important quantity that NRL would like to monitor. A system that would offer a means of interrogating this quantity as part of a future upgrade package would be desirable to NRL.