US 12,138,683 B2
Substrate-triggered directional solidification process for single crystal superalloy
Long Zeng, Shanghai (CN); Mingxu Xia, Shanghai (CN); Jun Li, Shanghai (CN); Binqiang Wang, Shanghai (CN); and Jianguo Li, Shanghai (CN)
Assigned to Shanghai Jiaotong University, Shanghai (CN)
Appl. No. 17/773,051
Filed by Shanghai Jiaotong University, Shanghai (CN)
PCT Filed Dec. 9, 2020, PCT No. PCT/CN2020/134913
§ 371(c)(1), (2) Date Apr. 29, 2022,
PCT Pub. No. WO2021/196713, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 202010234442.8 (CN), filed on Mar. 30, 2020.
Prior Publication US 2022/0395897 A1, Dec. 15, 2022
Int. Cl. B22D 27/04 (2006.01); C22C 19/05 (2006.01); C30B 11/02 (2006.01); C30B 11/14 (2006.01); C30B 29/52 (2006.01)
CPC B22D 27/045 (2013.01) [C22C 19/057 (2013.01); C30B 11/02 (2013.01); C30B 11/14 (2013.01); C30B 29/52 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A substrate-triggered single crystal superalloy directional solidification process, comprising:
a step (1) preparing a single crystal substrate material having crystallographic characteristics that match crystallographic characteristics of the single crystal superalloy;
a step (2) fabricating a single crystal substrate chilling plate using the obtained single crystal substrate material; and
a step (3) applying the obtained single crystal substrate chilling plate in a directional solidification apparatus, and then preparing a single crystal alloy product by performing superalloy melting and directional solidification,
wherein the crystallographic characteristics of the single crystal superalloy and the single crystal substrate material in the step (1) satisfy the following relation: a lattice mismatching degree between a crystal plane of the single crystal substrate material that contacts with the single crystal superalloy and a crystal plane of the single crystal superalloy is less than or equal to 7.8%,
wherein the single crystal substrate material in the step (1) is prepared through a grain selection directional solidification process, and is detected by using the following method:
ensuring a macrostructure of the single crystal substrate material is free of stray grains by using a sand blasting treatment and a macrostructure etching treatment;
performing an orientation test on the single crystal substrate material in which the macrostructure is free of stray grains by using Laue Diffraction; and
cutting the single crystal substrate material by using wire-cutting based on a test result of a Laue Diffractometer to obtain the single crystal substrate material with an expected crystal plane, and
wherein in the step (3), a melting temperature of the superalloy is 1450° C. to 1600° C., a pouring speed of a melted superalloy is 3°/s to 10°/s, and during directional solidification, heating temperatures for an upper furnace and a lower furnace are 1500° C. to 1600° C. and 1450° C. to 1550° C., respectively, and a pulling rate is 20 μm/s to 100 μm/s.