Effect of Heat Treatments on the Microstructural Evolution of a Single Crystal High-Entropy Superalloy
Takuma Saito,
Yung-Ta Chen,
Yuji Takata,
Kyoko Kawagishi,
Wei-Che Hsu,
An-Chou Yeh,
Hideyuki Murakami
Affiliations
Takuma Saito
Department of Nanoscience and Nanoengineering, Waseda University, Tokyo 169-8555, Japan
Yung-Ta Chen
Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
Yuji Takata
Research Center for Structural Materials, National Institute for Materials Science, Tsukuba 305-0047, Japan
Kyoko Kawagishi
Superalloys and High Temperature Materials Group, Research Center for Structural Materials, National Institute for Materials Science, Tsukuba 305-0047, Japan
Wei-Che Hsu
Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
An-Chou Yeh
Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
Hideyuki Murakami
Department of Nanoscience and Nanoengineering, Waseda University, Tokyo 169-8555, Japan
The effect of solution heat treatment as well as primary and secondary aging treatment conditions on the microstructural evolution of a high-entropy superalloy was investigated. The as-cast sample shows coarsened γ′ precipitates and other extra phases at interdendrite region due to microsegregation. This microsegregation makes γ′ solvus unclear and decreases the solidus. After conducting the solution treatment determined in this study, primary aging conditions showing an aligned cubic γ′ phase at 1050 °C for 4 h and random spherical γ′ precipitates at 950 °C for 20 h in similar size were found. By using both samples, secondary aging conditions showing coarsened secondary γ′ precipitates and γ particles inside the γ′ precipitates at 800 °C for 20 h and fine secondary γ′ precipitates at 850 and 870 °C for 20 h were found.
