In this work, in-situ TiB₂/2024Al composites were successfully fabricated by mechanical stirring and subsequent ultrasonic treatment. The effects of reaction temperature and enhanced phase mass fraction on the microstructure and mechanical properties of TiB₂/2024Al composites were studied. The results show that the reaction temperature affects the degree of reaction of the Al-Ti phase. When the reaction temperature is too low, a sheet-like Al-Ti intermediate phase still exists inside the melt. However, when the reaction temperature reaches 850°C, the Al-Ti phase is sufficiently dissolved and evolves into TiB₂ particles. The ability of TiB₂ particles to refine matrix structure was also discussed. As the mass fraction of TiB₂ particles increases, the matrix structure is continuously refined. When compared to the base alloy, the yield strength, tensile strength and elongation are significantly improved.

The dynamic recrystallization (DRX) behavior of as-extruded AM50 magnesium alloy was modelled and simulated by a cellular automaton (CA) method. Isothermal compression experiments were conducted, and the characteristic parameters in the CA model were obtained by the testing stress–strain flow curves in a wide temperature range of 250–450 °C and strain rate range of 0.001–10 s⁻¹. The flow stress, DRX volume fraction and DRX grain size of the as-extruded AM50 magnesium alloy were predicted by CA simulation. The results showed that the DRX behavior of the studied magnesium alloy was susceptive with the temperature and strain rate; meanwhile, the prediction results were approximate to the experimental values, indicating that the developed CA model can make a confident estimation on the DRX behavior of the as-extruded AM50 magnesium alloy in high temperature conditions.