Preparation of certified reference material of hydrogen in Al-Li alloys

The preparation process for certified reference material of hydrogen in Al-Li alloy has been introducedThe alloy was melted in atmosphereMeanwhile argon was used to prevent oxidation during meltingSome special process were adopted to keep the hydrogen content of alloy in about 1μg/gAfter melted,the alloy was casted to 120mm ingot by semicontinuous procedure with argon spraying meltingThe surface layer of the ingot was machined awayAfter homogenized the ingot was extruded into 10mm barsNo defect in the certified reference material was found by low-power microscope and the chemical composition of the certified reference material was homgenious. Hydrogen content was determined by different method,ieinduction-heating conductivity and impulse-heating conductivity,and different types of hydrogen determinator,the certified value of hydrogen content was accurate and reliable