TiC_p / 7075 铝合金热变形行为及微观组织演变

The hot compression deformation behavior and microstructure evolution of as-cast TiC_p / 7075 aluminum alloy with 3% TiC_p content were investigated. The hot compression deformation temperature range is 350- 550 ℃, and the solid solution temperature is 510 ℃. It is found that the grain size of the as-cast TiC_p / 7075 aluminum alloy is 50-150 μm, with TiC_p uniformly distributed macroscopically. Microscopically, most TiC_p coexist with the precipitated phase and are distributed along the grain boundaries, while a small amount of TiC_p undergoes agglomeration. The hot compression deformation ability is better at 350-500 ℃, but overburning occurs at 550 ℃ and further leads to deformation cracking. As the temperature increases, the metal flow becomes more intense, promoting the fragmentation and dissolution of η phase, which is conducive to the fragmentation and dispersion of TiC particles. At 500 ℃, η phase undergoes significant solid solution. Within the temperature range of 350-450 ℃, the weak dynamic recovery leads to a large amount of deformation energy storage, which can provide sufficient static recrystallization driving force during solution treatment. Meanwhile, TiC particles can act as nucleation sites to reduce the nucleation energy, resulting in obvious local static recrystallization. When the temperature is above 450 ℃, no significant static recrystallization occurs during solid solution due to the lower deformation energy storage.