Determination of hydrogen absorption and desorption processes in aluminum melts by continuous hydrogen activity measurements

Abstract

Continuous hydrogen activity measurement by pressure evaluation in liquid metals is a useful technique for the direct determination of hydrogen concentration changes in melts of aluminum and aluminum alloys and for the detection of sensitive steps in hydrogen absorption and desorption processes. This is demonstrated by various experiments performed with melts of pure aluminum. They show that undamaged pure Al2O3 oxide skins can prevent H2 absorption of aluminum melts and retard the desorption process to very low rates at temperatures below 800 °C.