Study On Die Casting Process And Microstructure And Properties Of 5A06 Aluminum Alloy Box

Aluminum alloy casting can not only make parts with various shapes and complex shapes,but also has good lightweight effect and mechanical properties.It is widely used in the manufacture of aircraft fuselages and electronic structural parts.As a rapid nearnet forming process,die casting is particularly suitable for the integrated design and integral forming of aluminum alloy thin-walled parts.This article takes 5A06 aluminum alloy thin-walled box body as the research object,and takes the influence of die-casting process parameters on the box formation and microstructure performance as the main research content.The relationship between them has been studied.The three-factor three-level orthogonal test method was used to simulate the die casting process of the box body casting process using Pro CAST software,and the effects of pouring temperature,mold preheating temperature and injection specific pressure on casting filling and solidification were analyzed.Using the filling time,solidification time and shrinkage percentage and other indicators to carry out the extreme analysis of the simulation results.After analysis and comparison,the optimal process parameter scheme for the die-casting forming of the aluminum alloy box was initially obtained: the pouring temperature was 670 ?,the mold preheating temperature was 200 ?,and the injection specific pressure was 120 MPa.Under this set of process parameters,the filling process of the box body is relatively stable,without turbulence,insufficient pouring,and splashing phenomena,and at the same time,the defects such as shrinkage and shrinkage holes in the casting are minimal.Then the actual production of the box body was carried out,and the box body was tested for non-destructive and airtightness.The results show that it has good consistency with the simulation,which fully proves the accuracy and the Guiding role in the actual production process.In order to more accurately determine the optimal process parameters of the aluminum alloy box die casting forming,orthogonal test design and range analysis were used to explore the effects of different die casting factors and levels on the mechanical properties of the box die casting.Then the influence of different die-casting process parameters on the structure and performance of the box body was studied by the control variable method.The research results show that the tensile properties of the box die casting are most affected by the injection specific pressure,followed by the pouring temperature,and the mold preheating temperature is the smallest.It was finally determined that when the casting temperature was 670 ?,the mold temperature was200 ?,and the injection specific pressure was 120 MPa,the mechanical properties of the casting reached the best level,of which the tensile strength of the casting was 232.5MPa,and the elongation after break was 4.16%.At this time,the appearance of the diecasting is well formed,the crystal grains in the casting are fine and uniform,and the defects such as holes are the least.By observing the fracture of the tensile specimen,the tearing edge and the dissociation platform can be found,so the fracture mode is judged to be cleavage fracture.In order to eliminate the internal stress of the die-casting parts and try to further improve the mechanical properties of the box body die-casting parts,the box body diecasting parts were artificially aging treated,and the microstructure and mechanical properties of the castings under different aging temperatures and aging times were analyzed.The results show that the aging treatment has a certain effect on the mechanical properties of the box die casting.After 240 ? and 4 h of heat preservation,the tensile strength increased by 14.28% and the elongation decreased slightly.Observation of the fracture morphology of the tensile specimen after aging treatment shows that the fracture mode is also cleavage fracture.