Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 13 No. 4 August 2003|
（Department of Mechanical Engineering,
Tsinghua University, Beijing 100084, China）
Abstract:Nucleation of gaseous hydrogen bubbles is the initial stage of GASAR process. Through the theoretical analysis, it has been identified that heterogeneous nucleation of bubbles as caps on the solid surfaces of impurities is impossible and only the heterogeneous nucleation in pits and cracks in impurities is the most feasible way in the GASAR process. The results also show that the probability of bubble nucleation progressively decreases from Al, Cu and Ni to Fe molten metal, which is the result of the increasing adhesion work of liquid metal on alumina.
Key words: GASAR; porous metal; bubble nucleation