Effect Of Hot Extrusion And Heat Treatment On Microstructure And Properties Of 2A14 Aluminum Alloy

2A14 alloy was studied by hot extrusion,heat treatment experiment,metallographic microstructure observation,scanning microstructure observation?SEM?,energy dispersive spectroscopy,transmission electron microscopy?TEM?and mechanical properties in this paper.The microstructures and mechanical properties of the alloys were investigated under different extrusion ratios,and the effects of the heat treatment on the microstructure and properties of the alloys were investigated.The results show that the internal structure of the alloy during hot extrusion process is re-crystallization,and the internal dislocation density of the alloy is low.The strengthening effect of hot extrusion on the alloy is the result of the combined effect of deformation strengthening and dynamic recrystallization.The second phase delaies the dynamic recrystallization rate by pinning dislocations and grain boundaries.With the increase of the extrusion ratio,the microstructure of the alloy shows uniform distribution and the second phase particles are evenly distributed,the size is smaller and the deformation strengthening effect is enhanced,which greatly improves the mechanical properties.The main strengthening phases of the extruded 2A14 alloy are ??Al₂Cu??Mg₂Si and co?Cu₄Mg₅Si₄Alx?,the main impurity phases are?FeMnSi?Al₆ or?FeMn?Al₆ The influence of four factors on the tensile strength of heat treatment are as follows:aging time,solid solution temperature,aging temperature and solid solution time.It was found that the higher the solution temperature,the greater the proportion of the second phase particles dissolved in the matrix,which provided favorable conditions for subsequent aging strengthening.After aging treatment,there were a large number of Cu precipitation,so was Mg.and theta phase and S phase?Al₂CuMg?were formed in the alloy matrix,and may contain a small amount of Omega phase.These strengthened phases have very uniform distribution with small size,which play an important role in alloy strengthening.The experimental results show that the tensile strength of the material is 352.7 MPa and the elongation is 15.3%under the condition of extrusion ratio of 36:1,after 505 °C×1.5 h solution treatment and 160?×8 h aging treatment.