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Johns Hopkins APL and Navy Chart Next Steps to Accelerate 3D-Printing Advancements
Hunter Turco, a senior mechanical fabrication technician, adjusts parts on a 3D printer in one of APL’s fabrication facilities. APL installed an identical machine on board the USS Bataan (LHD 5) last October and helped sailors print replacement parts for the ship while at sea.
Credit: Johns Hopkins APL/Ed Whitman
Ever made a mistake while sketching or writing in permanent ink and wanted to adjust your work — or scrap the whole thing altogether and start again? If so, you’ve utilized in situ monitoring. It’s a technique used in a variety of industries to monitor the production of something in real time and ensure defect-free items. It’s also become increasingly important in the field of additive manufacturing.
“In traditional manufacturing, such as welding, a real person is operating the equipment, and the welder can adapt as they go,” explained Michael Presley, a manufacturing engineer and project manager at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland. “In additive manufacturing, we currently have open-loop systems in which we set parameters and the machine begins manufacturing on its own. The machine can lay miles of welds without ever knowing if something goes wrong. By utilizing in situ monitoring technologies, we can spot those errors earlier if they arise and develop more efficient and accurate processes.”
These monitoring technologies cover a range of sensing modalities: systems ranging from cameras to pyrometers and thermocouples (devices that measure temperatures); spectrometers (that measure wavelengths of light to identify chemicals and materials) tuned across the infrared, visible, ultraviolet and X-ray spectrums; displacement sensors; profilometers (that measure the roughness of a surface’s finish); ultrasonic transducers (that generate or sense energy, often vibration); and even microphones — just to name a few. This wide scope arises from the complexity of the additive manufacturing process. Engineers need systems that concurrently measure the temperature and surface behavior of a molten metal drop moving at meters per second across a build plate, the quality of the bulk material it leaves behind, and the system health of all the lasers, pumps, actuators and feedback controls used by the machine.
Anticipating an Urgent Need
Integrating the wide range of technologies at the heart of in situ monitoring is a large systems-engineering challenge — and one of increasing importance to the Navy’s manufacturing base. While speaking on a panel in London, U.S. Air Forces in Europe Commander Gen. James Hecker said the U.S. stockpile of weapons and munitions is getting “dangerously low.”
And to further support the Department of Defense’s deterrence plans, the Navy plans to invest roughly $132 billion to acquire 12 Columbia-class submarines — the largest and most complex submarines in Navy history. But a recent Government Accountability Office report noted there could be trouble delivering those ships on time.
To address these manufacturing challenges, the Navy is prioritizing the development and fielding of additive manufacturing systems, often called 3D printers, to supplement traditional casting methods and accelerate submarine production. To support this effort, APL hosted a working group in July to discuss the current state of in situ monitoring in additive manufacturing, identify opportunities for advancement, and develop a path forward for future Navy implementation of such technology.
“Collaboration is going to be key in addressing both logistics and sustainment challenges in the current fleet and force and the manufacturing challenges of our future fleet and its weapon systems,” said James Borghardt, APL’s Maritime Expeditionary Logistics program manager. “We’re looking forward to our continued work with the Navy, Department of Defense and partner organizations to keep the field moving forward.”
The event was managed by team members from APL’s Force Projection Sector, Air and Missile Defense Sector, and Research and Exploratory Development Department with support from the Naval Sea Systems Command (NAVSEA 05T) and the Program Executive Office, Strategic Submarines. Among the 32 participating organizations were the Applied Research Laboratory at Penn State University, Virginia’s Commonwealth Center for Advanced Manufacturing, America Makes, the Army Research Laboratory, Naval Air Systems Command, the Office of Naval Research, Oak Ridge National Laboratory, the Defense Logistics Agency, the Nuclear Regulatory Commission and a range of Naval Surface Warfare Centers.
“We went from having a few dozen people in the Navy studying and monitoring additive manufacturing capabilities to now having hundreds,” said Presley. “And we’re trying to bring everyone up to speed and move as fast as possible because these are real, near-term needs. In situ monitoring will play a vital role here because it can speed up and improve inspection of additive manufactured parts.”
The In Situ Monitoring Working Group gathered at APL for a two-day event in July that brought together industry and government partners to identify tools and methods that can improve the Navy’s reliance on additive manufacturing.
Credit: Johns Hopkins APL/Ed Chapman
Creating Structure for Collaboration
Because additive manufacturing itself is relatively new, the additive manufacturing tools, data and standards being deployed are also new. July’s working group meeting was meant to bring the brightest and sharpest minds in the field into one room, and deliver tangible next steps to push the field, and the military’s trust and resiliency in such capabilities, forward.
“Efforts right now are sort of individualized across organizations, so we wanted to bring everyone together and tell each other what we’re learning, what we’re working on and what could be improved,” Presley continued.
The content of the meeting quickly expanded beyond what most were anticipating. “We thought we’d discuss what technology we needed, but we found out that we actually have a lot of what we need,” said Presley. “Now, we need to start collaborating as a community more, comparing data and figuring out what will be most useful for us in the future.”
Some of the most common findings were the need for standards development, efficient and secure sharing of sensor data, common calibration samples, and improved awareness and communication about the field and industry.
APL analyzed the discussions, notes and statements — which included nearly 2,000 sticky notes from 59 participants from the two-day event — to develop and deliver a report to the Navy that is being used to help the department set funding priorities for next year. The report analysis identified clear focus in the community on standardization and analysis of in situ sensor performance and data generation, with recommended courses of action including standardized calibration protocols, defining sensor-specific and material-dependent acceptance and rejection criteria, and prioritizing sensor data to capture.
“To fully capture the potential value in additive manufacturing, based on the working group’s findings, we are working with the Navy to focus on qualifying or certifying the advanced manufacturing process through in situ monitoring and data analytics instead of the traditional process of qualifying individual parts,” said Borghardt. “The potential to democratize the industrial base and engage small businesses is both challenging and very exciting.”
Sailors 3D-Print Critical Component at Sea Using Johns Hopkins APL-Installed Hybrid Manufacturing System → Nov 13, 2023
