The　solid　fraction　at　the　beginning　of　the　forging　process　is　an　important　factor　affecting　the　performance　of　the　casting-forging　integrated　forming,　which　is　an　innovative　and　efficient　process.　The　solid　fraction　depends　on　the　delayed　forging　time　during　the　casting-forging　integrated　forming.　This　paper　investigates　the　effect　of　delayed　forging　time　on　the　microstructure　of　aluminum　alloy　forged　during　solidification　using　an　innovative　physical　simulation　method.　In　this　work,　a　solidification-forging　device　compatible　with　the　Gleeble　system　has　been　developed.　Then,　experiments　were　conducted　at　various　delayed　forging　time.　Temperature　and　force　data　were　collected　using　the　Gleeble　system　for　analysis.　Microstructural　evolution　was　investigated　using　methods　including　Optical　Microscopy　(OM),　Scanning　Electron　Microscopy　(SEM),　Electron　Backscattered　Diffraction　(EBSD),　and　Three　Dimensional　Computed　Tomography　(3D-CT).　The　results　demonstrate　that　with　the　extension　of　the　delayed　forging　time,　the　grain　size　of　the　alloy　decreases　gradually,　and　the　coarse　dendrite　structure　changes　to　the　rose-shaped　grains,　and　the　local　misorientation　in　the　grain　increases.　Moreover,　the　effect　of　forging　under　different　forging　time　on　the　casting　defects　of　the　alloy　is　studied.　When　the　forging　delay　is　extended　to　8　s,　the　forging　promotes　the　porosity　caused　by　the　liquid　phase　convection.　However,　with　further　extension　of　forging　delay,　the　reduction　of　the　liquid　phase　and　the　fracture　of　dendrites　lead　to　the　complexity　of　liquid　phase　channels,　resulting　in　the　increase　of　porosity.　Additionally,　forging　near　solidification　can　close　shrinkage　porosity.　©　2024　The　Authors