Combustion of Thermites in Reduced Gravity for Space Applications

摘要

Fabricating and repairing techniques based on the combustion of thermite mixtures are of great interest for space applications due to the low-energy consumption and self-sustained behavior of the involved chemical reactions. Two such techniques investigated in the present paper are exothermic welding and the combustion-based production of structural materials from lunar regolith. In both cases, the occurring combustion of thermite-type mixtures may be affected by reduced gravity. In the present paper, experiments on the exothermic welding of copper rods and on the combustion of a lunar regolith simulant mixed with magnesium were conducted during the parabolic flights of reduced-gravity research aircraft. In the welding experiments, using a spring mechanism for the movement of a molten welding material did not result in a strong weld. In the experiments with regolith, a slight effect of the gravity on the combustion front velocity was observed. The product compositions are in a reasonable agreement with thermodynamic calculations.