中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 36 No. 1 January 2026 |
（a Department of Inorganic Materials, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China;
b Hunan Key Lab of Mineral Materials and Application, Central South University, Changsha 410083, China;
c Engineering Research Center of Ministry of Education for Carbon Emission Reduction in Metal Resource Exploitation and Utilization, Central South University, Changsha 410083, China）
Abstract:Some active metal oxides (Al2O3, TiO2, and Cr2O3) were selected as dopants to the Al2O3-based ceramic shells for investment casting of K417G superalloy. The effects of dopant types and contents (0, 2, 5, and 8 wt.%) on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment. The results show that increasing the Al2O3 doping contents (0-8 wt.%) reduces the porosity (21.74%-10.08%) and roughness (3.22-1.34 μm) of the shell surface. The increase in Cr2O3 dopant content (2-8 wt.%) further exacerbates the interfacial reaction, leading to an increase in the thickness of the reaction layer (2.6-3.1 μm) and a decrease in the wetting angle (93.9°-91.0°). The addition of Al2O3 and TiO2 dopants leads to the formation of Al2TiO5 composite oxides in the reaction products, which effectively inhibits the interfacial reaction. The increase in TiO2 dopant contents (0-8 wt.%) further promotes the formation of Al2TiO5, which decreases the thickness of the interfacial reaction layer (3.9-1.2 μm) and increases the wetting angle (95.0°-103.8°). The introduced dopants enhance the packing density of the shell surface, while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.
Key words: Al2O3-based ceramic shell; K417G superalloy; metal oxide dopants; interfacial reaction; wettability
