Defense
By Gretchen Salois, senior editor
Printing metal parts is changing the way the U.S. military responds to shortages, supply chain hold-up
T

he technology that moves us forward, affording people flexibility amid urgent situations, often makes its first inroads within the laboratory setting. Research continues to advance alloys to lighten the weight of vehicles as well as qualify more intricately printed parts. In metal fabrication, the military has installed its first metal printing solution to aid soldiers located far from the supply chain.

Where you really get the benefit of using additive manufacturing is you’re able to print crazy, organic designs that are both lightweight and structurally robust. You simply couldn’t create the part any other way.
Dr. Brandon McWilliams, U.S. Army CCDC
3D printing technology developed at U.S. Army CCDC will enable soldiers to print replacement parts for vehicles such as the M1 Abrams tank. Photo: Cpl. Israel Chincio / U.S. Marine Corps
Defense
By Gretchen Salois, senior editor
Where you really get the benefit of using additive manufacturing is you’re able to print crazy, organic designs that are both lightweight and structurally robust. You simply couldn’t create the part any other way.
Dr. Brandon McWilliams, U.S. Army CCDC
3D printing technology developed at U.S. Army CCDC will enable soldiers to print replacement parts for vehicles such as the M1 Abrams tank. Photo: Cpl. Israel Chincio / U.S. Marine Corps
Printing metal parts is changing the way the U.S. military responds to shortages, supply chain hold-up
T

he technology that moves us forward, affording people flexibility amid urgent situations, often makes its first inroads within the laboratory setting. Research continues to advance alloys to lighten the weight of vehicles as well as qualify more intricately printed parts. In metal fabrication, the military has installed its first metal printing solution to aid soldiers located far from the supply chain.

At the U.S. Army Combat Capabilities Development Command (CCDC), Army Research Laboratory in Adelphi, Maryland, Dr. Brandon McWilliams is a steadfast presence who pursues the latest technological advances to help make creating parts more efficient and attainable for ground vehicles.

“We develop and transition research to help move the process along and other departments can then focus on sustainment such as replacement parts, reducing long lead times, etc.,” McWilliams says. “We develop the recipe in our labs and hand it off.”

In 2019, McWilliams printed short-term-use empeller fans for M1 Abrams tanks. Since then, researchers are working to implement long-term metal printed solutions in the coming months. “The next group plugs and plays and goes into production mode,” he says.

Alloy design
Printing complex geometries for high wear-and-tear parts that meet stringent tolerances includes delving into new alloys for Army applications. McWilliams’ team is analyzing new structures to lightweight materials and to modernize long-range fire and next-generation combat vehicles.

“We’re figuring out how to achieve the complexity and design while working with new materials, including more affordable high-strength steel alloys,” he says.

Adjusting alloy composition is important for the next stages of additive manufacturing. In the lab and in the field, the Army is printing different compositions of parts, including those that call for greater hardness and toughness—“parts that can withstand the stresses of ballistics requirements,” McWilliams says. “If you look at any ground vehicle, the M1 Abrams, Bradley tanks—each are basically a box manufactured with flat plate. They were designed in the 1960s so we know we can [reduce] weight and increase performance as well as advance the overall vehicles’ designs.”

U.S. Marine Corps Staff Sgt. Quincy Reynolds
The printer lets us make anything from a complicated part to a standard screw. What would have taken weeks or months now takes on average a week to complete.
U.S. Marine Corps Staff
Sgt. Quincy Reynolds
Reynolds places a 3D-printed part
A) U.S. Marine Corps Staff Sgt. Quincy Reynolds is a machine shop staff noncommissioned officer with General Support Maintenance Company, 3rd Maintenance Battalion, Combat Logistics Regiment 35, 3rd Marine Logistics Group in Okinawa, Japan.

B) Reynolds places a 3D-printed part onto a furnace plate to be transformed into its densest form.

C) A finished part is placed into a Markforged Wash-1, which is used to debind and dry 3D-printed parts.

D) Reynolds and Cpl. Chase Ramsby modify parts using SolidWorks before 3D printing.

E) After the part has finished printing, it is ready to be washed and dried.

Photos: Lance Cpl. Armando Elizalde, 3rd Marine Logistics Group
After the part has finished printing
A finished part is placed into a Markforged Wash-1
U.S. Marine Corps Staff Sgt. Quincy Reynolds
The printer lets us make anything from a complicated part to a standard screw. What would have taken weeks or months now takes on average a week to complete.
U.S. Marine Corps Staff
Sgt. Quincy Reynolds
Reynolds places a 3D-printed part
A finished part is placed into a Markforged Wash-1
Reynolds and Cpl. Chase Ramsby modify parts using SolidWorks before 3D printing
After the part has finished printing
A) U.S. Marine Corps Staff Sgt. Quincy Reynolds is a machine shop staff noncommissioned officer with General Support Maintenance Company, 3rd Maintenance Battalion, Combat Logistics Regiment 35, 3rd Marine Logistics Group in Okinawa, Japan.

B) Reynolds places a 3D-printed part onto a furnace plate to be transformed into its densest form.

C) A finished part is placed into a Markforged Wash-1, which is used to debind and dry 3D-printed parts.

D) Reynolds and Cpl. Chase Ramsby modify parts using SolidWorks before 3D printing.

E) After the part has finished printing, it is ready to be washed and dried.

Photos: Lance Cpl. Armando Elizalde, 3rd Marine Logistics Group
Coupling materials and design involves addressing structure as well as elements like heat transfer. “Where you really get the benefit of using additive manufacturing is you’re able to print crazy, organic designs that are both lightweight and structurally robust. You simply couldn’t create the part any other way,” McWilliams says.

Prior research tended to be more siloed into materials development, but additive “has made this more exciting. We’re tied to applications whereas before, we were more looking at one part of the process and not working together. The speed with which additive is advancing design and materials is amazing.”

Printing with titanium powder is nothing new but adjusting other alloy properties continues to aid in driving down printing costs.

“We’re working to tweak Inconels, high-strength steels, aluminum, magnesium as well as working on how we can adjust titanium to make working with that material more cost effective,” McWilliams says.

Where titanium would not typically be used for parts in a traditional setting due to cost, printing to create an exact part without waste does make sense.

Welding a groove
(Above and bottom, right)
Airman 1st Class Taylor Dow uses augmented reality system to train on welding a groove well at Dyess Air Force Base, Texas. The augmented reality system is split into three training operations for welding: metal inert gas, tungsten inert gas and arc welding. Photos: Staff Sgt. David Owsianka
Airman 1st Class Joshua Wetzel
Airman 1st Class Joshua Wetzel welds two steel plates together to stay current on his tee joint welding certification. Photo: Senior Airman Austin Siegel
Training operations for welding
AS ALLOYS AND FABRICATION TECHNIQUES ADVANCE, military instructors are employing technologies that make training more efficient. For the last seven months, for example, Technical Sgt. Gregory Kirchner, a specialist in Air Force Aircraft Metals Technology, says augmented reality has played a large part in training new airmen to weld.

“It will typically take someone 200 to 300 welds to become proficient for aircraft quality welds so getting the basics down using this technology saves us a lot of resources,” Kirchner says.

Training experienced welders may prove more difficult than new recruits. “Welding is a very personal thing—you have your own technique so it takes us a little more time to get used to virtual guidance indicators,” he continues.

Welders are responsible for supportive equipment repairs using MIG welding. Inspection differs depending on where the part is used.

“For aircraft parts, we have to verify multiple components from structural criteria by using X-rays; and we are limited to one inclusion that is five times the thickness of one strand of human hair,” Kirchner says.

When aircraft parts are certified, “they have to be textbook perfect,” he says. “And because we’re always shooting for perfect, making mistakes via augmented reality is helpful because it tells you [where the mistake occurred] without going through thousands of physical pieces of steel sheet. We decreased the amount of steel used by 75 percent.”

Welders typically weld stainless steel but are also using aluminum, titanium and exotic alloys.” This compares with the past, “when we used [carbon] steel and magnesium,” Kirchner says.

Technology goes beyond augmented reality as the Air Force prepares to use handheld scanners that will allow for 3D scanning.

“Any part brought in that we need to reverse engineer will be much easier because instead of manually drawing up calculations, the scanner will take a read,” Kirchner says. “For more advanced brackets, using this tool could eliminate 70 to 80 hours worth of programming.”

A goal is to further drive down the cost of raw materials, and thereby parts, by using alternatives to titanium where possible.

Actual alloy characteristics hold the key to accelerating materials development, says McWilliams. “We’re working with alloy grades that are 70 years old,” he says. Alloy development and design involve computational work. New design processes are limited as long as the alloys remain static. “As they currently exist, these alloys aren’t optimized for this process.” Researchers must use digital design tools to develop future additive applications and, eventually, “we’ll be light years ahead of where we started.”

Fully operational
In Okinawa, Japan, the Marine Expeditionary Force (MEF) maintains a “fight tonight” status, no matter the situation. Marines prepare for myriad situations including combat, humanitarian aid or disaster relief in the Indo-Pacific region.

Within the metal fabrication department, U.S. Marine Corps Staff Sgt. Quincy Reynolds at Camp Kinser uses the Marines’ first Metal X 3D printer to print parts otherwise difficult to procure. The flexibility to print on premise is invaluable as the 66-mile-long island relies on supplies from the mainland. About 26,000 U.S. military personnel inhabit the island, spread among 32 bases and 48 training sites.

“Here in Okinawa, there can be a logistics hassle when ordering certain parts with lead times up to six months,” Reynolds says. “The printer lets us make anything from a complicated part to a standard screw.”

Reynolds and the MEF are printing parts for a variety of platforms, including satellite equipment, vehicle engine parts, as well as optics equipment. Fabricators use superalloys such as Inconel, stainless steel, tool steel and copper. “By printing parts, we save time,” Reynolds says. “What would have taken weeks or months now takes on average a week to complete.” When parts are needed quickly, there is no need for subtractive manufacturing (CNCs), jigs or step-by-step part making. The MEF fabricators have used the printer to create dedicated stands at the ready to rebuild gas or diesel engines. “An engine comes in and we can place it on the dedicated stands and bolt on whatever parts are needed,” Reynolds says.

Marines use SolidWorks software to design test parts in plastic before printing them using metal. “Once we’re sure the part is the right dimensions, we launch it into the Metal X printer so the Marine can then step away and work on something else,” Reynolds says. “Conventional ways would require having an operator or machinist present, working through each step, but with the printer you hit print, wait for the base layer, and that’s it. You don’t have to stand in front of it and watch it.”

Marines learn CAD/CAM SolidWorks software in order to reverse engineer parts. “With this basic understanding, there is very little learning curve because it’s similar to subtractive manufacturing,” Reynolds explains.

Eiger 3D printing software removes much of the manual calculating a fabricator would otherwise be required to perform. “Once we put the file into the Eiger slicing program, it converts the file to a thumb drive and the Marine puts the drive into the metal printer,” Reynolds explains.

This 3D-printed butterfly assembly
This 3D-printed butterfly assembly is for an M4A1 carbine part for an assault rifle.

Photo: Lance Cpl. Armando Elizalde, 3rd Marine Logistics Group

Using the Metal X printer, the operator can input a 20 percent infill, choose a hexagon or triangular pattern, and figure out the needed tensile strength. “Once, we printed a socket and it failed when torque was applied. We increased the infill to 100 percent during socket printing and were able to apply 200-ft.-lbs. of torque without failure to the printed socket. The head of the bolt sheared, but the printed socket remained intact,” Reynolds says.

New filaments, including copper, continue to open up ways additive manufacturing can be used to print cooling fans for logistics tools, or “anything, really,” Reynolds adds. “The future using 3D printing is unlimited. We can go anywhere from here but we’re still figuring it out with every new request that comes in.”