Researchers explore additive manufacturing
July 2, 2014
- In the next 10 to 15 years, experts expect the technology to revolutionize how commercial and defense products are designed, sourced and sustained.
Army Technology Magazine
- July/August 2014 Focus: 3-D Printing
ABERDEEN PROVING GROUND, Md. (July 2, 2014) -- In past 30 years, 3-D printing has transformed from an immature technology with limited applications to being adopted by industry as an enabler for the next generation of products and systems.
In the next 10 to 15 years, experts expect the technology to revolutionize how commercial and defense products are designed, sourced and sustained.
"As the technology continues to mature, the Army must not only closely watch how industry is applying this game-changing manufacturing process, but also have an active role in shaping the technology, applications and reducing the barriers to implementation within Army systems," said Andy Davis, Army Manufacturing Technology program manager. "The benefits of actively participating in the advancement of 3-D printing to the Army are great."
Whether it is manufacturing parts on demand at the point of need, repair of high-value parts at a fraction of the cost and time, or realizing entirely new designs currently unobtainable through traditional manufacturing processes, the Army of the future will rely on this additive manufacturing process, he said.
Additive manufacturing is the process of building a 3-D structure by introducing material to a space that previously had none. This is opposed to traditional subtractive process, which starts with a block of material and subtracts material until arriving at a target final geometry.
Within additive manufacturing, there is 3-D printing. Davis said the terms are not synonymous.
"You could consider welding to be additive," he said. "You are introducing a filler material into a base material to join them and perhaps build up a surface. 3-D printing is specifically related to taking what looks like a printer, a print head, and you're extruding material, or you are using a laser to melt material and consolidate it, layer-by-layer into a three-dimensional form. It can be metal, plastic or organic materials."
Because 3-D printing is layer-by-layer building of parts, the process is flexible and enables users to produce almost any geometry conceivable.
"Coupled with the reality of being able to minimize or eliminate support tooling, 3-D printing has nearly limitless applications," Davis said.
In 2011, President Barack Obama initiated the National Network of Manufacturing Innovation. This network is part of a larger plan focused on strengthening the U.S. economy by investing in advanced manufacturing. As a result, the U.S. government, led by the Departments of Defense and Energy, established a series of manufacturing institutes, similar to the Fraunhofer Institute model seen throughout Germany.
"These are public--private partnerships focused on specific technology areas really aimed at research and technology development that can be commercialized," Davis said. "The first of the U.S. government-backed manufacturing institutes, known as America Makes, is focused on 3-D printing. The Army has been involved in America Makes from the start. It is a great opportunity to align our expertise, personnel and investments in 3-D printing with what's going on at a national level."
The Army's ManTech Program and Army science and technology community, through the U.S. Army Research, Development and Engineering Command, provides subject-matter experts, requirements, funding and leverages a much larger community of practice to include government, industry and academia.
Requirements drive the Army science and technology. The U.S. Army Training and Doctrine Command looks to the S&T community to inform the establishment of requirements. Army acquisition program managers often turn to the RDECOM community and seek help from Army researchers, engineers and scientists to help meet those requirements.
"3-D printing has been a technology and a capability that, by and large, has moved forward without requirements," Davis said. "It can do a lot of things. It can do everything, depending on who you listen to. Should it? No, it probably shouldn't do everything."
Future requirements under development at TRADOC may include the capability for a Soldier to download a part file out from a master parts library; print the part; take the part off the machine; put it on a system and accomplish his or her mission.
"That's the vision," Davis said. "The Army must focus on technology development and policy advances to achieve this vision. From a technology and processing standpoint, 3-D printing is limited based on material properties and structural strength of the end item being produced.
"Take the drive wheel on a tank, for example," Davis said. "It is forged from a very specific alloy of steel or aluminum, which gives it specific properties. This part has been tested and qualified and validated that the design, material and process are correct given the requirements. You may not be able to get those material properties and performance from a 3-D printing process."
If one starts with a powder versus a block of metal that is hammered into a final shape, the process is inherently different from the traditional manufacturing process.
"As a result, there are differences in what the end product will be," he said. "Policy also dictates some of the barriers to implementing 3-D printing as a viable manufacturing solution across the materiel enterprise. Specifically, part and process qualification rise to the top of the list of challenges. Set 3-D printing aside. If you want to change something that was an aluminum honeycomb structure to a composite structure, it is challenging and expensive. It is time-consuming and very costly to get through a flight certification process for a traditionally manufactured part. Now you're introducing not just a new part that's been made using traditional manufacturing processes, you're introducing a whole new manufacturing process that's not yet well-characterized. Our acquisition policy must reflect new ways of dealing with this challenge."
"The Army needs to be looking at the parts and the materials for our systems that go above and beyond commercial industry needs," Davis said. "We must develop the material data sets, processing parameters, and library of parts that are approved or qualified using a certain process. We need a central repository for the digital part and processing data necessary to build and maintain our systems. We need to have control over that so that there's not long-term uncertainty in sourcing those parts. We need to be able to disseminate this information to users in the depots and in the field.
"We have parts that come back from the field because they are slightly worn," he said. "Consider the main rotor shaft for a helicopter -- to replace one can cost tens of thousands of dollars and may take several months depending on the supply chain. Imagine the savings to the Army in terms of operational availability and cost if those parts could be repaired, in the field or at a depot, using 3-D printing technologies."
RDECOM has teams working with Army depots to do just that, but more effort is required to qualify these processes, Davis said.
The Future is Now
The Army will get to a point where it can print and build parts using additive processes that are combined with subtractive processes, Davis said.
"Someday that will all be integrated. It will be the right part, right off the machine, all the time. But, that is a ways off," he said. "RDECOM needs to be looking at the materials sets and the requirements. We need to partner with the commercial and defense industrial base, with academia and with other government agencies to address technology and policy challenges.
"We also need an industrial base that is capable of making things for us. The future of an integrated additive-subtractive manufacturing industry that enables Soldiers to manufacture finished end-items at the point of need begins with the Army focusing on 3-D printing technologies and policies to enable the use of these technologies today."
The U.S. Army Research, Development and Engineering Command is a major subordinate command of the U.S. Army Materiel Command. AMC is the Army's premier provider of materiel readiness -- technology, acquisition support, materiel development, logistics power projection, and sustainment -- to the total force, across the spectrum of joint military operations. If a Soldier shoots it, drives it, flies it, wears it, eats it or communicates with it, AMC provides it.