Thermwood tests 3D printed carbon fibre-filled PPS panels without coatings

Thermwood has taken a major step toward its goal of 3D printing autoclave capable tooling from high temperature carbon fibre filled thermoplastic materials.

The manufacturing company 3D printed 50% carbon fibre-filled PPS panels on its LSAM additive manufacturing machine, maintaining the part’s vacuum to an industry-standard level, without coatings. Testing of the part was conducted by the Fleet Readiness Center, located at MCAS Cherry Point, NC, under a previously announced Cooperative Research and Development Agreement (CRADA) partnership. The results met FRC-East acceptance criterion that the bag must not lose than more than 2 in Hg over five minutes.

As an added benefit, Thermwood believes it will soon be capable of producing moulds and tooling that function properly under vacuum in a heated, pressurized autoclave, also without the use of any type of coating to seal the printed tools.

Previously, other unaffiliated companies have tested actual tools printed by Thermwood from 20% Carbon Fibre-filled ABS and have also found that those tools held vacuum to an acceptable level without the use of any sealer or coating; however, the ABS material is not suitable for high temperature applications.

Yet, several parts have been made from those tools under vacuum at room temperature and at slightly elevated temperatures. Thermwood has also already printed a 50% Carbon Fibre-filled three dimensional PPS mould which has not yet been tested. Thermwood’s goal is to produce moulds that will be used in a production autoclave, moulding finished parts suitable for actual end use.

Thermwood’s additive printing process differs fundamentally from conventional Fused Deposition Modelling (FDM) printing. Most FDM processes print parts by melting and extruding a relatively small bead of thermoplastic material onto a heated build plating that is contained within a heated chamber. The heated chamber keeps the extruded material from cooling too much before the next layer is added.

Thermwood machines print a large bead at such a high rate that a heated environment is not needed. It is basically an exercise in controlled cooling. Print speed is adjusted so that each layer cools to the proper temperature just as the next layer starts to print resulting in a continuous printing process that produces high quality parts. Thermwood believes this fundamentally different approach produces superior parts.

One other feature that Thermwood engineers believe helps produce solid, void free parts, is a patent pending compression roller that follows directly behind the print nozzle, flattening the bead while fusing it tightly to the previous layer.

Orbital ATK Tests 3D Printed Hypersonic Engine Combustor, Tastes Success

Earlier this week, American aerospace manufacturer and defence industry company Orbital ATK tested a 3D-printed hypersonic engine combustor at NASA’s Langley Research Center in Virginia.

It has been an eventful month for the US-based firm; a $47 million contract from the US Air Force Space and Missile Systems Center for an Evolved Expendable Launch Vehicle (EELV) program for national space security missions is now followed by this path-breaking testing mission.

The scramjet, or the supersonic combusting ramjet combustor is one of the most challenging parts of a propulsion systems. Here, the jet is propelled by combustion which takes place in supersonic airflow. A scramjet relies on high vehicle speed to forcefully compress the incoming air, hence they key is efficient operation at high speed. This scramjet component spent a thorough 20-day period in high-temperature hypersonic flight conditions and at the same time, underwent one of the longest wind propulsion tunnel tests at Langley.

Orbital-ATK-Combustor.

The combustor was assembled by a process called Powder Bed Fusion (PBF), where a layer of metal alloy is laid down by the printer and a laser or electron beams fuses areas of it by following a digital pattern. Following this layer-by-layer process, the excess powder is removed and the component is smoothened. Pat Nolan, Vice President and General Manager of Orbital ATK’s Missile Products division remarks that this process is as necessary as it efficient since the complex design of the combustor would otherwise require multiple parts and a much more arduous manufacturing technique.

The tests served a dual objective: observing the effectiveness of the 3D printing process, and concluding if the finished product met its mission objectives, and Orbital ATK claims both of these were satisfactory.

The 3D printing process was completed at the company’s Ronkonkoma, New York facility and the Allegany Ballistics Laboratory in Rocket Center, West Virginia.

Source: Orbital ATK and Gizmag

ESA successfully tests 3D printed thruster

The European Space Agency (ESA) has successfully test fired a 3D printed platinum alloy thruster combustion chamber and nozzle. The world first test is further evidence that the 3D printing approach is a viable one for the aerospace industry, with the potential to cut costs by streamlining production methods and adding a greater level of flexibility in terms of supply and demand construction.

The 10 N hydrazine thruster combustion chamber and nozzle was printed in layers from a platinum-rhodium alloy, using a laser printing machine ordinarily used for creating jewelry. The engine was then put through 618 ignition tests during which reached a maximum temperature of 1253 °C (2287 °F). According to ESA, theses results are on a par with thrusters produced via conventional machining methods.

“The aim was to test this alternative manufacturing method as a way of reducing material costs,” states ESA engineer Laurent Pambaguian regarding the project. “At the start we were by no means certain it could be done, or even whether the metal powder could be prepared to the appropriate quality.”

The thruster component prior to testing

By printing a component layer by layer, a manufacturer produces only negligible amounts of waste when compared to the standard technique, which involves creating the combustion chamber from a solid block of material. The waste, and therefore expense, of so unrefined a process mounts when one considers that Airbus Defence & Space produce 150-200 hydrazine thrusters each year and that platinum currently costs €40 (US$63) a gram.

SpaceX has also been experimenting with 3D printing. Back in 2014 the company finished qualification testing for its SuperDraco thruster, which also featured a 3D printed combustion chamber made from a nickel-chromium alloy.

With multiple agencies and commercial companies embracing the potential of 3D printing in the aerospace sector, we are sure to see the technology become heavily relied upon as we set our sights ever deeper into space. It will influence the design of future spaceships, and is likely to play a part in the construction of outposts on other planets and moons.

The next step for ESA and its partners will be to print the components out of a new alloy, platinum–iridium, which offers performance enhancements over platinum-rhodium.

Source: ESA

NASA Hot-fire Tests First Ever 3D Printed Rocket Engine Injector

nasa-3We have already seen several incredible applications of 3D printing and its connection to space travel. Both NASA, and Elon Musk’s SpaceX are pushing the boundaries of the technology in several directions, in the process taking advantage of the infinite complexity that additive manufacturing puts into the hand of designers and engineers. With 3D printing, almost anything seems to be possible.

Back in May, SpaceX showed off their new SuperDraco Thrusters which will go on their Dragon Version 2 spacecraft.  These thrusters featured engine chambers which were completely 3D printed. According to the company the thruster allowed them to conserve weight and save money, allowing them to create more complicated components using less individual parts.

It was just a matter of time until we would see similar approaches taken by NASA in their construction of rocket engines for their high powered spacecraft. Afterall they already are deeply involved in the additive manufacturing space, expected to take a 3D printer to the International Space Station later this year, and working to 3D print an entire space telescope. That time has seemingly come, as NASA has just unveiled a rocket engine injector, the first of its kind to ever be 3D printed. In fact, they had two such injectors produced by two different companies, Solid Concepts in Valencia, California, and Directed Manufacturing in Austin, Texas, each tested for 5 seconds at a time.  Yesterday they released footage of one engine injector undergoing a hot-fire test at their Marshall Space Flight Center in Huntsville, Alabama.

nasa-1

The part, which is crucial to the engine’s performance, is responsible for sending propellant into the engine. It mixes hydrogen gas, and liquid oxygen together, which combusts at a quite balmy 6,000 degrees Fahrenheit, producing an incredible 20,000 pounds of thrust.

“We wanted to go a step beyond just testing an injector and demonstrate how 3-D printing could revolutionize rocket designs for increased system performance,” said Chris Singer, director of Marshall’s nasa-2Engineering Directorate. “The parts performed exceptionally well during the tests.”

The injector features 40 individual spray nozzles, 3D printed as a single piece. The entire injector is made up of just 2 parts, whereas, if this component was to be manufactured by traditional methods, there would be 163 different individual parts included. You can imagine why such new techniques are saving NASA, as well as other companies a tremendous amount of time and money, while allowing for complexity which would never have been imaginable without additive manufacturing.

“Having an in-house additive manufacturing capability allows us to look at test data, modify parts or the test stand based on the data, implement changes quickly and get back to testing,” said Nicholas Case, a propulsion engineer leading the testing. “This speeds up the whole design, development and testing process and allows us to try innovative designs with less risk and cost to projects.”

The tests were an overwhelming success, with the injectors performing to standards. Imagine the time the agency can save by simply being able to print new designs within hours, instead of having to wait weeks or even longer to have new parts created via injection molding for testing. The number of applications within engine manufacturing should continue to expand as NASA begins to understand the possibilities that this technology can bring to the table.

Let’s hear your thoughts on this recent accomplishment within the NASA 3D printing forum thread on 3DPB.com. Check out the video of the 5-second hot-fire testing of the engine injector below.

[youtube http://www.youtube.com/watch?v=nyveRd36FR8]