Microstructure and properties of K648 superalloy additively manufactured by extreme high-speed laser metal deposition
(1. College of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China;
2. State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China;
3. School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China;
4. Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong 999077, China)
2. State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China;
3. School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China;
4. Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong 999077, China)
Abstract: In order to improve the manufacturing efficiency of high-chromium superalloys, an innovative extreme high- speed laser metal deposition (EHLMD) process was used. The growth behavior of precipitated phases, high-temperature mechanical properties, wear resistance, and corrosion resistance of EHLMD K648 superalloy were investigated and compared with conventional laser metal deposition (CLMD) using transmission electron microscope, tensile tester, wear tester and electrochemical workstation, respectively. The results reveal that the precipitated phase size in EHLMD K648 superalloy is significantly smaller than that in CLMD K648 superalloy. Moreover, EHLMD K648 superalloy demonstrates higher tensile strength at 700 °C, superior wear resistance, and excellent corrosion resistance compared to CLMD K648 superalloy. Consequently, the K648 superalloy manufactured through EHLMD technique exhibits favorable comprehensive properties.
Key words: additive manufacturing; extreme high-speed laser metal deposition (EHLMD); K648 superalloy; microstructure evolution; properties