Effect of Strontium on the Oxidation Kinetics of Aluminum Conductor Alloy AlTi0.1 in the Solid State

Interaction of aluminum conductor alloy AlTi0.1 (Al + 0.1 wt % Ti) containing 0.01, 0.05, 0.1 and 0.5 wt % strontium additives with atmospheric oxygen in the range 723–823 K without formation of a liquid phase has been investigated by the thermogravimetric method. The kinetic parameters, true rate constants and activation energies of the oxidation process were determined for the studied compositions. It was revealed that, with an increase in the strontium content from 0.01 to 0.5 wt %, the oxidation rate of the initial alloy AlTi0.1 increases with a simultaneous decrease in the apparent activation energy of the oxidation process from 140.0 to 116.9 kJ/mol. An increase in the oxidation rate is explained by the interaction of strontium oxide with aluminum oxide with the formation of spinel, which simplifies the access of oxygen to the reaction surface. The oxidation kinetics of alloys is approximated by a hyperbolic law.