Supercorroding Alloys for Ocean Applications

A family of supercorroding magnesium alloys that react spontaneously and vigorously with seawater have been developed at CEL. Investigations of the mechanical and corrosion properties of the alloys show that they are useful for heat and hydrogen gas generation as well as for self-destructing linkages for retrieval of oceanographic instruments. Alloys of magnesium with different cathode materials were fabricated and tested. Results of tests with powdered and compacted and sintered forms of the alloys are presented. A powdered magnesium alloy with 5 atomic percent iron produced 950 ml of hydrogen per gram of alloy and 13.3 K joules of heat per gram. One gram is over 90% reacted within one minute from immersion. Compacting and sintering produced a barstock with a tensile strength of 60 M pascals. This same material had a surface corrosion rate of m per hour. Time-to-failure for barstock material, 1.07 cm square, under a 5.33 kg tensile load while immersed in seawater was found to be 14 hours.