A research team led by Penn State has secured a $1 million grant from DARPA’s Structures Uniquely Resolved to Guarantee Performance (SURGE) program to develop new quality control methods for metal 3D printing. The two-year project aims to detect porosity defects in metal parts during the printing process rather than after completion. The team will incorporate acoustic sensors into printing platforms and use ultrasonic microphones to identify flaws in real-time.
Christopher Kube, associate professor of engineering science and mechanics at Penn State, will lead the multidisciplinary team. Co-principal investigators include Penn State faculty members Allison Beese and Andrea Argüelles, along with Northwestern University’s Tao Sun. Their approach leverages the fact that melt pools in laser-based metal printing emit distinctive acoustic tones when bubbles form.
“Our technique is based on stimulating the melt pools with short duration ultrasonic waves such that the bubbles ‘sing’ to the acoustic microphones installed within the build chamber,” Kube explained. The research will utilize high-speed X-ray imaging at Argonne National Laboratory’s Advanced Photon Source to provide reference data for interpreting acoustic signatures during printing.
Current metal 3D printing processes require post-production inspection using X-ray computed tomography, which adds time and cost to manufacturing. The team’s goal is to develop a technique that can reliably measure 25-micron subsurface pores and locate them within 125 microns during printing. This capability could significantly improve production efficiency for defense applications.
Testing will occur at both Penn State and the Advanced Photon Source, with a final demonstration planned for late 2026 using a laser powder bed fusion 3D printer at Penn State. The project represents one of only four teams selected to participate in the DARPA SURGE program, which focuses on high-risk, high-reward research initiatives.
Source: psu.edu
