D. Hadjiapostolidou, B. A. Shollock, Imperial College London, London, United Kingdom
René 80 is a high volume fraction Ni-based superalloy used in turbine blades. Its good mechanical properties (rupture stress at 870°C 350MPa for 100h and 240MPa for 1000h, at 980°C 160MPa for 100h and 105MPa for 1000h) as well as microstructural stability during engine operation allow its use at elevated temperatures. The influence of temperature and time on the microstructure of René 80 after long term aging was examined. The alloy was subjected to various heat treatments in the temperature range of 850°C – 1,050°C for 1,000h – 20,000h. The microstructural evolution was characterised with both scanning and transmission electron microscopy. The characteristics of γ' (gamma') particle distributions were measured using image analyser software. The average particle radius was compared to the cube-rate law and the particle size distributions (PSD) for the populations of γ' (gamma') precipitates were compared with theoretical models.
Summary: Ren¨¦ 80 is a high volume fraction Ni-based superalloy used in turbine blades. Its good mechanical properties (rupture stress at 870¡ãC 350 MPa for 100h and 240 MPa for 1000h, at 980¡ãC 160 for 100h and 105 for 1000h) as well as microstructural stability during engine operation allow its use at elevated temperatures. The influence of temperature and time on the microstructure of Ren¨¦ 80 after long term aging was examined. The alloy was subjected to various heat treatments in the temperature range of 850¡ãC ¨C 1,050¡ãC for 1,000 h ¨C 20,000 h. The microstructural evolution was characterised with both scanning and transmission electron microscopy. The characteristics of ¦Ã¡¯ particle distributions were measured using image analyser software. The average particle diameter was compared to the cube-rate law and the particle size distributions (PSD) for the populations of ¦Ã¡¯ precipitates were compared with theoretical models.
