Hydrogen gas porosity

Hydrogen forms whenever molten aluminium comes into contact with water vapor, and easily dissolves into the melt.

Hydrogen causes porosity in aluminum products leading to many casting defects, reduced mechanical properties like fatigue and lower corrosion resistance.

Traditional laboratory methods, such as hot extraction, are too expensive for routine quality assurance, and too slow for effective process control.

Direct monitoring of hydrogen is possible using an on-line quantitative measurement technology based on a closed-loop gas recirculation method though a porous ceramic probe.

The amount of H2 in the gas loop of the instrument is determined by a thermal conductivity sensor, which provides high reproducibility and a broad measurement range.