Rapid post processing of cold sprayed Inconel 625 by induction heating

• Main Authors: Wu, Kaiqiang, Aprilia, Aprilia, Tan, Sung Chyn, Zhou, Wei
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Article
• Language: English
• Published: 2023
• Subjects: Engineering::Mechanical engineering; Cold Spray; Post Processing
• Online Access: https://hdl.handle.net/10356/169324
• Institution: Nanyang Technological University

Cold spray is a solid-state metal deposition technology. One of the major advantages of cold spray over other additive manufacturing technologies is the high deposition rate. Heat treatments are usually conducted for cold sprayed deposit to improve its ductility; however, the long duration of conventional furnace heating would compromise the advantage of fast deposition. The current work explored the use of induction heating to accelerate the heat treatment process. A post-process heat treatment of cold sprayed Inconel 625 by induction heating was carried out at 900 °C for 10 min. Microstructure, hardness, ductility, and adhesion strength of the cold sprayed Inconel 625 deposits were systematically studied before and after the induction heating. For comparison, the conventional furnace heat treatment was also conducted with the same heating temperature and duration. Compared with furnace heating, induction heat treatment yielded larger grain size and larger δ precipitates due to enhanced atomic diffusion promoted by the eddy current. There was a significant improvement of ductility of the Inconel 625 deposit after induction heat treatment, and this can be attributed to enhanced inter-splat bonding. In contrast, the improvement of ductility by furnace heating was limited. The adhesion strength was found to increase more significantly by induction heating when the thickness was within the penetration depth of the eddy current. The results show that rapid post processing of cold sprayed Inconel 625 can be achieved by induction heating.