中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 35 No. 10 October 2025 |
（1. National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001, China;
2. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
3. College of Materials and Metallurgy, Guizhou University, Guiyang 550025, China）
Abstract:The microstructure and creep behavior of C/Y2O3 synergistically micro-alloyed high-Al and low-Al TiAl alloys prepared by induction skull melting (ISM) technology were investigated by advanced electron microscopy. Microstructure analysis shows that Y2O3 particles are dispersed in both alloys; element C is dissolved in low-Al alloys as solid solution, while it exists as Ti2AlC particles within lamellae in high-Al alloys. Additionally, high-density nanotwins are generated in high-Al alloys. Creep data show that C/Y2O3 micro-alloying significantly enhances creep resistance of TiAl alloys. This benefits from the dispersion strengthening of Y2O3 particles, precipitation hardening of dynamically precipitated Ti3AlC particles and lamellar stabilization caused by dissolved C atoms or Ti2AlC particles. This strategy causes a more significant improvement on creep resistance of high-Al TiAl alloys, which is attributed to extra twin strengthening effect. At 775-850 °C, these alloys fracture in mixed ductile-brittle mode, but the fracture characteristics change with the increase of temperature.
Key words: micro-alloyed TiAl alloy; creep behavior; twin strengthening; carbide precipitation; fracture characteristics
