Spooky Manufacturing: Probabilistic Sabotage Attack in Metal AM using Shielding Gas Flow Control.

Metal Additive Manufacturing (AM) is increasingly utilized for functional parts, often used in safety-critical applications such as jet engine components. For these applications, it is imperative that the fit, form, and function are not compromised. However, it has been shown that numerous intentional sabotage attacks are pos- sible. Understanding how sabotage attacks can be conducted is a prerequisite for their prevention and detection. This work focuses on Laser Beam Powder Bed Fusion (LB-PBF), an AM machine type dominant in the manufacturing of net-shape metal parts, and its subsystem controlling the shielding gas flow. We analyze how this essential subsystem can be manipulated to sabotage AM part performance. Our analysis shows that such sabo- tage attacks will be probabilistic, as opposed to the deterministic attacks previously discussed in the research literature. While this introduces issues with performance degradation and control over it, it is likely to also complicate the determination of intent and investigation of its root cause.