1. Microstructure and tensile properties optimization of MIM418 superalloy by heat treatment
- Author
-
Xuanhui Qu, Mingli Qin, Xinbo He, Lin Zhang, Dan Li, and Zhou Li
- Subjects
010302 applied physics ,Ostwald ripening ,Materials science ,Precipitation (chemistry) ,Metallurgy ,Metals and Alloys ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Indentation hardness ,Industrial and Manufacturing Engineering ,Computer Science Applications ,Superalloy ,symbols.namesake ,Precipitation hardening ,Modeling and Simulation ,Critical resolved shear stress ,0103 physical sciences ,Ultimate tensile strength ,Ceramics and Composites ,symbols ,0210 nano-technology - Abstract
Solution plus ageing leads to the precipitation of finer and more homogeneous γ′ precipitates in comparison to direct ageing. Solution treatment at 1220 °C eliminates the large primary γ′ phase and replaces them with homogeneous secondary γ′ precipitates. Coarsening of γ′ particles according to Ostwald ripening mechanism is confirmed. An increase of the critical resolved shear stress (CRSS) is observed for the under-aged specimens, followed by a maximum of CRSS at γ′ particle size of around 100 nm and a decrease of CRSS for the over-aged specimen. This result agrees well with the highest yield strength and microhardness of the 750 °C × 24 h aged specimens.
- Published
- 2016