Hydrogen diffusion coefficient in liquid metals evaluated by solid-gas eutectic unidirectional solidification
(1. School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China;
2. Key Laboratory for Advanced Materials Processing Technology of Ministry of Education,
Tsinghua University, Beijing 100084, China)
2. Key Laboratory for Advanced Materials Processing Technology of Ministry of Education,
Tsinghua University, Beijing 100084, China)
Abstract: Based on the solid-gas eutectic unidirectional solidification technique and the principle of unidirectional solidification of single-phase alloy, a new method for evaluating the diffusion coefficient of hydrogen in liquid metals was proposed. Taking Cu-H2 system for example, the influences of argon partial pressure and superheat degree of melt on the diffusion coefficient of hydrogen in liquid metal were studied and the predicted values were similar to each other. The obtained temperature-dependent equation for diffusion coefficient of hydrogen in liquid copper is comparable with experimental data in literature, which validates the effectiveness of this method. The temperature-dependent equations for diffusion coefficient of hydrogen in liquid Mg, Si and Cu-34.6%Mn alloy were also evaluated by this method, along with the values at the melting point of each metal and alloy.
Key words: hydrogen; diffusion coefficient; liquid metal; solid-gas eutectic; unidirectional solidification