The novel heat treatments of aluminium alloy characterized by multistage and non-isothermal routes: A review

Both preliminary heat treatment and final heat treatment play an irreplaceable role in the production of aluminum alloy products. The homogenization degree of compositions, the size of the dispersoid and its coherent relationship with the matrix, the size and aspect ratio of recrystallized grains, the supersaturation of solutes, and the characteristics of precipitates directly determine the mechanical properties, corrosion resistance, and the workability of materials. In engineering applications, non-isothermal phenomena involving heating and/or cooling processes are inevitable due to the impact of product scales. Therefore, novel heat treatment technology with higher engineering applicability is a necessary extension of the solid-state phase transformation theory. Based on the typical wrought aluminum alloys such as AlZnMg(Cu), AlMgSi, and AlCu(Li), the current researches on engineeringable homogenization, solid solution, and aging technologies were summarized. The novel technologies focused on multistage heat treatments and non-isothermal heat treatments.