The effect of Ti addition on the precipitation evolution for Al–7Si–Mg alloy was systematically investigated by combing high-resolution transmission electron microscopy (HRTEM) and first-principles calculations. At the early aging stage, the rod-shaped Al₃Ti and ellipsoid Ti₅Si₃ phases precipitated firstly, and the stronger Si capture ability of them suppressed the precipitation of the Mg–Si phases (β'' and β′), leading to the deceleration of the aging hardening kinetics. With prolonging aging time, one Al atom in Al₃Ti was easily replaced by Si atom to form a more stable Al₂SiTi phase. It was demonstrated by Energy Dispersive Spectrometry (EDS) and the calculation of formation enthalpy. The accurate atomic structure of the Al₂SiTi phase was also obtained, which provided a resonable speculation on the structure of Al₃Ti two-dimensional compound (2DC) containing Si on the surface of TiB₂. This shed light on a deep understanding of Si poisoning on grain refinement of Al–Si/Al–5Ti–B system. At the over-aged stage, the Mg–Si phases began to precipitate, preventing the decrease of the hardness. Finally, a new precipitation sequence in the Ti-rich Al–7Si–Mg alloy can be obtained: SSSS → Al₃Ti + Ti₅Si₃ → Al₂SiTi + Ti₅Si₃ → Al₂SiTi + Ti₅Si₃ + β" → Al₂SiTi + Ti₅Si₃ + β"+ β'.

通过结合高分辨率透射电子显微镜 (HRTEM) 和第一性原理计算，系统地研究了 Ti 添加对 Al-7Si-Mg 合金析出演变的影响。时效初期，棒状的Al ₃ Ti 和椭球状的Ti ₅ Si ₃相首​​先析出，它们较强的Si捕获能力抑制了Mg-Si相（β''和β'）的析出，导致时效硬化动力学的减速。_{随着时效时间的延长，Al 3} Ti中的一个Al原子容易被Si原子取代，形成更稳定的Al ₂SiTi 相。它通过能量色散谱（EDS）和地层焓的计算得到证明。_{还获得了Al 2} SiTi相的准确原子结构，为TiB _{2表面含Si的Al 3} Ti二维化合物（2DC）的结构提供了合理的推测。这有助于深入了解 Si 中毒对 Al-Si/Al-5Ti-B 体系晶粒细化的影响。在过时效阶段，Mg-Si 相开始析出，阻止了硬度的降低。最后，可以得到富钛 Al-7Si-Mg 合金中新的析出顺序：SSSS → Al ₃ Ti + Ti ₅ Si ₃ → Al ₂ SiTi + Ti ₅Si ₃ → Al ₂ SiTi + Ti ₅ Si ₃  + β" → Al ₂ SiTi + Ti ₅ Si ₃  + β"+ β'。