Embedding Sensors in an SS316 Matrix with Laser Powder Bed Fusion

The US Department of Energy’s Transformational Challenge Reactor (TCR) program was launched with the goal of designing and 3D printing a nuclear reactor core by leveraging recent advances in modeling and simulation, materials, manufacturing, and sensing. Using additive manufacturing, sensors can be embedded at critical locations for monitoring system performance and component health. This study demonstrates the ability to embed thermocouples in SS316 using laser powder bed fusion (LPBF). Channel dimensions and LPBF processing parameters were varied to optimize the melt pool to properly embed the sensors without damage to the sensing elements and ensure proper functionality after the embedding procedure. Microstructural characterization and mechanical indentation were performed to evaluate interfacial bonding. The optimum processing conditions for successful embedment will be discussed in conjunction with the observed microstructure and mechanical behavior. Finally, applications for embedded sensors within the TCR core will be discussed.