Citation: Mathew J, Havermann D, Polyzos D et al., Laser Powder Bed Fused Parts made of SS316 with Embedded Fibre Optic Sensors for Temperature Monitoring up to 1000°C. J 3D Print Addit Manuf. 2022;1: 1-6. 01 Coalesce Research Group International Journal of 3D Printing and Additive Manufacturing Laser Powder Bed Fused Parts made of SS316 with Embed- ded Fibre Optic Sensors for Temperature Monitoring up to 1000°C Research Article 2022: Volume 1, Issue 1 01 Received Date: 26-05-2022 Published Date: 08-06-2022 Jinesh Mathew 1,2* , Dirk Havermann 1 , Dimitrios Polyzos 1 and Robert R. J. Maier 1 1 Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh, UK 2 Department of Physics, GITAM School of Science, Bengaluru, India Corresponding author: Jinesh Mathew, Department of Physics, GITAM School of Science, India E-mail: jmathew@gitam.edu. Abstract A smart metal component with an integrated high temperature sensing capability is presented. The metallic structure in SS316 is manufactured by an additive layer process based on laser powder bed fusion (LPBF). The sensor, a temperature sensitive in-fiber Fabry-Perot element, is encapsulated in a capillary and embedded into the structure during the LPBF build process. It is demonstrated that the sensor can measure the temperature inside the metal up to 1000°C with accuracy better than 10°C for extended periods far in excess of 300 h. Introduction Laser-Powder Bed Fusion (LPBF) is rapidly becoming a highly versatile and important technology for the manufacture of complex shaped structures and components, often with highly intricate internal channels and designed- in voids for cooling and other functional capabilities [1,2]. In particular, power generation by gas turbines is an important technology where LPBF parts can drastically improve efficiency and operational lifetime. There are by now numerous other application areas and materials which benefit and gain functionalities from additive manufacturing technologies and the technology described here can be adapted and moved to other techniques although different temperature limits will apply depending on the material matrix used [3-5]. Integrating high temperature sensing capability into power generation components is increasingly important for real-time process condition monitoring and asset management. Such sensors must be capable of sustained high temperature operation and hence fused silica optical fibre sensors are an obvious choice; the high softening point of fused silica means that such sensors should be capable of operating at temperatures in excess of 1100°C, with a Fabry-Perot (F-P) design suitable for temperature measurement in this range[6,7]. Additive manufacturing involves building up structures layer by layer and it opens up the prospect of incorporating valuable internal features into structural components during their manufacture. A smart metal fabrication process has been developed which is based upon laser additive manufacturing (3D printing) to incorporate optical fiber sensors into metallic components during their construction [8, 9]. The paper here describes the manufacture of LPBF manufactured coupons with integrated temperature sensors as substitute to the integration into actual turbine components for technology demonstration. These coupons can be manufactured in 10 minutes whereas a turbine part requires 2-3 hours processing time Recent studies on the temperature characteristics of an embedded fiber Bragg grating (FBG) in a metallic structure show that due to the coefficient of thermal expansion (CTE) mismatch between silica and the host metal the differential strain at elevated temperatures can lead to delamination and fiber breakage [9-13] and limiting its application to ~450°C. Therefore, a different approach has been used in this paper in which a high temperature compatible F-P fiber sensors is encapsulated inside a fused silica capillary, in the metal