Evolution of microstructure and mechanical performance of plasma-sprayed Ti–Cr–Si–C coatings annealed at 800 °C and 1100 °C. (February 2022)

• Record Type: Journal Article
• Authors: Li, Suyun; Fang, Haixiao; Jiao, Qi; He, Jining; Zhao, Hongjian; Qin, Yanfang; Yin, Fuxing
• Is Part Of: Vacuum. Volume 196(2022)
• Publication Date: 2022-02
• Subjects: Ti-Cr-Si-C coating -- Plasma spraying -- Annealing -- Microstructure -- Fracture toughness; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2021.110781
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: In this work, Ti–Cr–Si–C coatings were plasma sprayed from Ti/Cr/Si/graphite powders and their microstructure evolution and mechanical properties after annealing at 800 °C and 1100 °C were studied. Ti–Cr–Si–C coatings were sprayed with a lamellar structure and they consisted of TiC, Ti5 Si3, MAX-Ti3 SiC2, Cr, unreacted Si and graphite. After annealing at 800 °C and 1100 °C, MAX-Ti3 SiC2 phase increased and the microstructure became more uniform because of Ti/Si/C/Cr element diffusion. The average micro-hardness of plasma-sprayed 3Ti–Si–2C–Cr coating improved by 2% after annealing at 800 °C and its average fracture toughness improved by 18%. The average micro-hardness of plasma-sprayed 3Ti–Si–2C-1.5Cr coating improved by 9% after annealing at 1100 °C and its average fracture toughness improved by 22%. The improved mechanical properties were because of the increased MAX-Ti3 SiC2 phase, the uniform microstructure and the micro-cracks healing, indicating the annealing treatments were positive for the performance of Ti–Cr–Si–C coatings. Highlights: MAX phase increased and the microstructure became more uniform after annealing. The micro-cracks tended to heal after annealing. The micro-hardness and fracture toughness of Ti–Cr–Si–C coatings improved by 2–9% and 15–22% after annealing.