In the years leading up to World War II, the US military had the opinion that it was technologically equal to any adversary in the world. On December 7, 1941, and for years afterward, US military discovered it was not. America did have the advantage of the strongest manufacturing base but it took time to retool to military products. America mainly won the day because of overwhelming numbers of men and equipment. In the beginning, the US tanks and aircraft were woefully inferior. The aircraft built by the US later caught up and surpassed the Axis capabilities (the Axis jets arrived too late to make a difference). America’s tanks never caught up. But American know-how on the battlefield made a difference everywhere. This can be seen in the M4 Sherman medium tank. Several modifications were made in the field by the soldiers themselves. For example, soldiers modified the tank to literally cut through the thick hedgerows in the Normandy countryside. However, many lives were lost because of inferior technology not just in the military but because the conflict was lengthened.
After the war, the newly created Department of Defense (DoD) analyzed what had gone right and also what went wrong. Government military labs grew and the DoD became more proactive in acquiring and developing new technology. One of the results of this mindset was the creation of the Defense Advanced Research Projects Agency (DARPA). The genesis of that mission and of DARPA itself dates to the launch of Sputnik in 1957, and a commitment by the United States that, from that time forward, it would be the initiator and not the victim of strategic technological surprises. It was working with DARPA that my group witnessed the origins of additive manufacturing, then referred to as rapid prototyping, in the first 3D Systems machine in 1986.
Defense facilities nationwide started using additive manufacturing (AM) technologies early on in the ’90s. But as the technologies have become more robust and have better materials, DoD entities warmed to the idea of putting these technologies to use directly. All branches have now implemented plans not only to use AM in the development of systems but the forward deployment of additive manufacturing in critical areas.
The US Navy is advancing its plan to use AM to improve fleet maintenance and operations at three different levels. At Level 1—Organizational Level, AM will be used at the squadron level for mission support and through servicing of aircraft and replacement parts. At level 2—Intermediate Level at Fleet Readiness Centers, AM will manufacture components of engines, scheduled maintenance, and in-service repair. At Level 3—the Depot Level, AM will assist in scheduled maintenance, modifications, in-service repair, field team in-service repair, and manufacturing.
The Navy has nine Fleet Readiness Centers (FRCs) equipped with AM technology. Five are on the East Coast, three more on the West Coast, and one in Japan. The FRCs are using AM for several applications, such as form blocks and stretch and bladder press components in sheetmetal tooling, and they’re also using traditional AM in fit-form and rapid prototyping. FRCs are using FDM (fused deposition modeling) for shop tooling guides, jigs, and fixtures. AM software exists that can automatically create jig and fixture AM files based upon CAD geometry and the CNC machine that is used. You can now retool quickly overnight with an ability to make modifications and fixes to parts to meet new mission requirements. AM machines also produce composite parts, and the FRCs produce composite tools as well.
Finally, the most important application is using AM for end-use parts. There are two categories for this application. One is described as Near Term Work in Progress. This describes parts that are used as quick fixes or for mission modifications. The other category is for Longer Term components made using metal AM machines that make parts from titanium, cobalt chrome, and steel alloys. This is where the military is emphasizing in future planning. Look for traditional contracts for DoD to specify that parts include AM files for replacement parts as well as part-build parameters and postprocessing procedures.
On January 23, 2017, there was an AM demonstration of these capabilities at the Naval Air Station located at North Island, CA. Material engineers demonstrated a cold spray process to repair aircraft components. The additive, solid-state thermal spray can restore components’ critical dimensional features that have been lost due to corrosion, wear or mechanical damage. Other additive technologies such as laser cladding are also being looked at for repairing critical parts.
The US Army has a history of using AM at its bases and the Army gets first acknowledgement for the use 3D printing down range in the fight. The Rapid Equipment Fielding (REF) expeditionary lab for rapid prototyping was deployed in Afghanistan in May 2012. The REF’s lab has already seen success in rapidly producing solutions to problems within days. For example, soldiers were experiencing problems with the life of a battery on a mine detector system. The battery, which was supposed to last six to eight hours, would work for only about an hour in the heat in Afghanistan. Within six hours of a soldier coming into the lab, the engineers created an adapter that connected to the battery that allowed charging with any military standard battery, and increased the battery life to 48 hours.
However, the original use of AM technology is still one of the best with its role in prototype deliverables and the ability to not just try a design but to use the full IQ power of engineers and soldiers by trying multiple solutions to a problem at the same time.
The Army’s Armament Research, Development and Engineering Center (ARDEC) and the Edgewood Chemical Biological Center (ECBC) are doing significant AM work. Rick Moore, branch chief, rapid technologies and inspection, said, “For 20-plus years ECBC has exploited the benefits of AM for form, fit, and function prototypes throughout all phases of rapid product development. With the continuous maturation of AM and steadily increasing confidence levels in the performance of the technology, DoD is experimenting with applying AM at the point-of-need in the battlefield. This paradigm shift in the implementation of AM has the potential to reduce supply chain burden and maintain readiness levels.”
At ECBC, researchers work in a lab with a number of high-end AM machines designing printable holders for the military bomb detectors. The Army ECBC produced thousands of the holders designed to take weight off soldiers’ backs. Rick Moore stated that, “The fact that we could do this many designs and print them out and have them in their hands in one week gave the Army the option to choose between what works best for their application. This is a good example of how we use the technology every day.”
The Anniston Army Depot is using a form of directed energy deposition AM, called Laser Engineered Net Shaping (LENS) from Optomec, to repair the Abrams Compensating Suspension Arm. Because only worn surfaces are repaired using a wear-resistant material with minimum heat effect on the original part, there are significant cost savings. Replacement cost of the suspension arm is $2000 and repair cost is $750, resulting in a savings of $1250 for each arm. The Army’s AM effort is guided by the US Army Organic Industrial Base Strategic Plan (AOIBSP), which attempts to provide a highly responsive and cost-effective enterprise. Currently, the AOIBSP covers only the Army’s five primary maintenance depots (Sierra, Red River, Corpus Christi, Anniston, Letterkenny, and Tobyhanna) and three manufacturing arsenals (Pine Bluff, Rock Island, and Watervliet).
The Air Force has spearheaded much of the development of AM in recent years, and there have been many reports of additive manufacturing of jet components by the Air Force and its contractors. But the Air Force has other important plans for AM, such as the manufacturing of customized parts featuring complex geometric shapes at low production quantities that can help maintain an aging aircraft fleet. Custom tools, engine components and lightweight parts can enable better maintenance and aircraft longevity. The Air Force recently reported that AM can address a multitude of challenges and that it plans to implement these processes from the logistics community. It is recognized that the fleet is aging and replacement parts for planes built 30 years ago often no longer exist. The rapid production of a small number of hard-to-find parts is extremely valuable and cost effective, and 3D imaging and related software are finally at the state where parts can be scanned in, translated into an accurate CAD model and 3D printed.
What is exciting about this is that with additive manufacturing techniques, old aircraft can be not only maintained but mission-modified in order to meet the need of an ever-changing world of combat.
Food for the Warfighters
An interesting development is the US Army researching the 3D printing of food to meet the Army’s needs. The main benefit would be to cut costs, because food could be produced on demand which would eliminate waste and logistic costs. It would also give soldiers more of a choice in menu. Nutrition is one of the primary goals. The physical and mental stress on combat soldiers is extreme, and maintaining the optimal state of a soldier’s body and mental condition is critical to the mission and safety. Imagine a day where food could be stored almost indefinitely in homes for emergency situations with an almost inexhaustible variety of menu options.
How many times have you felt tired or under the weather? Pharmacies will be equipped with a machine that analyzes your blood and prints out a nutrition bar with the right nutrients, electrolytes, carbohydrates, and amino acids, etc.
The US military also is partnering with the AM industry. Military personnel are attending the AM conferences, getting involved, presenting and sitting on panels, providing input that helps drive these technologies. They are hosting events and providing much needed research funds to make these technologies more practical and dependable. This is especially seen in the research into new metal alloys in additive manufacturing. The reason for this effort is that the military sees the future in additive manufacturing and realizes that additive manufacturing is a big solution for many of the problems of the future battlefield. In addition, the military is looking hard at 4D printing and in situ circuits and sensors. There are several new offerings including embedded circuitry inside the part, and in the near future, aircraft wings will have in situ sensors and body armor with built-in communications, environmental feedback, and bio-monitoring systems.
Since World War II, the military has had the advantage over its adversaries in the use of superior technology. In recent years, the military not only been proactive in the use of additive manufacturing but has championed development of these technologies for reliable and practical use. The results are an improved state of readiness for the military where systems can be more quickly manufactured, repaired, and maintained. In the future, there will be a need for less storage of parts, reducing the need for warehouse expenditures. Additive manufacturing will give forward areas the ability to develop solutions on their own and maintain men and material assets. But one very notable gain will be that the military will be much leaner. They will be able to do more with less. |||