Effect of hydrogen pressure on pore growth and microstructure of GASAR porous Mg–Ag eutectic alloys

• Published in: Vacuum Vol. 217; p. 112552
• Main Authors: Li, Hong, Li, Zaijiu, Jin, Qinglin, Xia, Chenping
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-11-2023
• Subjects: Eutectic transition; GASAR process; Mg-Ag eutectic alloy; Pore growth; Pore growth; Eutectic transition; Mg-Ag eutectic alloy; GASAR process
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2023.112552

In order to study the effect of hydrogen, as a third non-metallic component, on the macroscopic pore growth and eutectic solidification structure in the directional solidification process, GASAR porous Mg–Ag eutectic alloy ingots were prepared by mould casting technology at different hydrogen pressures. The results show that with an increasing hydrogen pressure, the increased temperature gradient promotes the nucleation and growth of pores; for the microstructure, the increased temperature gradient cause an increasing driving force for solidification structure growth, which leads to the instability of the eutectic cells, and the eutectic structure transitions from lamellar to rod-like.
•Porous Mg–Ag eutectic alloy were successfully fabricated by the GASAR process.•The temperature gradient increases with the increasing hydrogen pressure.•The gradually increased temperature gradient promoting the nucleation and growth of pores.•The eutectic structure transitions from lamellar to rod-like with an increasing temperature gradient.