<p>Solid solution treatment is a common heat-treatment method for aluminum alloys. However, the traditional solid solution treatment in heating furnaces takes a long time and has low thermal efficiency. This paper used 6082-T6 Al alloy as the research object and studied the dissolution behavior of the second phase during the contact solid solution process using TEM and XRD. The results showed that a 2&#xa0;mm 6082-T6 Al alloy sheet completed solution treatment in 28&#xa0;s, which was much shorter than the 1800s required in the heating furnace. The main reason was that the extremely high heating rate of the contact solid solution inhibited the transformation and coarsening of the Mg₂Si phase, achieving rapid solid solution. Anchored in the established principles of dissolution kinetics, the study highlighted the effects of the secondary phase’s particle aspect ratio and heating rate. A dissolution kinetics model specifically for the Mg₂Si phase, in agreement with contact solid solution theory, was formulated and showed excellent agreement with experimental results.</p>