Embedding thermocouples in SS316 with laser powder bed fusion*

Recent advances in manufacturing technologies have enabled the fabrication of complex geometries for a wide range of applications, including the energy, aerospace, and civil sectors. The ability to integrate sensors at critical locations within these complex components during the manufacturing process could benefit process monitoring and control by reducing reliance on models to relate surface measurements to internal phenomena. This study investigated embedding thermocouples in a SS316 matrix using laser powder bed fusion. Under optimal processing conditions, embedded thermocouples were characterized post-building, finding good bonding to the matrix with no melt pool penetration to the sensing elements. Moreover, the embedded thermocouple performed similarly to an identical non-embedded thermocouple during thermal testing to 500 degrees C with only a slight difference in response time, which was attributed to the differences in mass and the associated thermal time constants.