Monitoring strain evolution and distribution during the casting process of AlSi9Cu3 alloy with optical fiber sensors

Recent advances in optical fiber high-temperature sensors and encapsulation technique [Invited]

“…Research groups from Technical University of Munich and Munich University of Applied Sciences have used FBG/RFBG sensors to monitor the high-temperature metal casting processes in the past several years. Those FBG/RFBG sensors, in direct contact with metal, could survive after the casting process with the maximum temperature of 650°C and compressive strain-10,000 με for aluminum [31,137] and 1100°C and 14,000 με for Cu [112] . The cast parts with embedded optical fibers were further manufactured into standard tensile test specimens to achieve tensile tests, and simultaneously temperature and strain measurement [138] .…”

“…However, due to the significant temperature changes during the casting process and the huge difference in CTEs between the metal and silica, this process often introduces significant compressive strain, typically exceeding −10,000 με, under which ordinary optical fibers cannot survive after exposure to high temperatures. To solve this problem, optical fibers with larger dimensions and higher mechanical strength are used [112,137] . Additionally, it should be noted that during some encapsulation technique processes, high-temperature adhesive is used for bonding, and the mismatch in its CTE can also lead to a deterioration in the final encapsulating effect [173,174] .…”

“…Carbon steel structure corrosion monitoring 2021 [133] Magnetron sputtering and electroplating -194°C-20°C Temperature measurements or temperature compensation in cryogenic engineering 2023 [134] Electroless plating and electroplating Up to 545°C High temperature strain structural health monitoring 1991 [135] Casting Casting aluminum < 200°C Monitoring and mechanical system 2018-2023 [31,137] Casting aluminum/Cu Up to 650°C Structural health monitoring of metallic structures 2002 [146] Laser additive manufacturing Magnetron sputtering, electroplating and LASDM…”

Heat Treatment Optimization for a High Strength Al–Mn–Sc Alloy Fabricated by Selective Laser Melting

“…Selective laser melting (SLM), as a widely employed additive manufacturing (AM) technology, is an emerging technology in the energy, aerospace, and medical fields [1,2]. Compared to conventional manufacturing techniques of casting [3], rolling [4], forging [5], and extrusion [6], SLM utilizes its flexible manufacturing characteristics to directly fabricate geometrically complex parts, layer by layer, through precise control of a high-energy laser beam on the metallic powder bed. The highly localized melting, the ultra-fast cooling rate (10 5 -10 6 K/s), and the extremely high temperature gradient (G-10 6 K/m) allow the formation of extraordinary non-equilibrium microstructures and excellent mechanical properties in SLM manufactured parts [7,8].…”