Modeling of Isothermal Dissolution of Precipitates in a 6061 Aluminum Alloy Sheet during Solution Heat Treatment

During the solution heat treatment (SHT) process of aluminum alloys, precipitates dissolve into the matrix. To predict the dissolution time, modeling of isothermal dissolution of precipitates in 6061 aluminum alloy during SHT was conducted. A precipitate dissolution model was established, and the flowchart of the modeling was designed as well. Then the explicit finite-difference method was employed to solve the dissolution model, and the mobile nodes method was used to deal with the moving interface. The simulation was based on real precipitates in 6061, and SHT experiments were conducted to validate the numerical model. The simulation results showed that the isothermal dissolution time of precipitates in 6061-T6 aluminum alloy at 560 °C is 11.6856 s. The dissolution time in the simulation was close to the experimental results, with an error of 16.7%, indicating that the modeling in this study was fairly reasonable and accurate. The error was caused by many factors, and the model should be improved.