Study On The Microstructure And Texture Of The 6016 Aluminum Alloy Body Sheet During The Processing Procedures

Automobile lightening plays growing important role on achieving a low-carbon life through energy-saving and emission reduction. While, aluminization of automobile materials is an important way of car lightening. So, improving the formability and age hardening properties of 6000 aluminum alloy is of great importance for strength enhancement and solving the forming problem of irregular shape parts.6016 aluminum alloy, for example, the microstructure and texture during the hot and cold deformation were studied by the means of orientation mapping based on EBSD technique and the x-ray diffraction technique, through the hot rolling experiment, and hot simulation experiment and cold rolling experiment. And through the solid solution and aging experiments, the evolution law of microstructure and texture in the solid solution procedure,the aging precipitation behavior, bake hardenability and formability were studied by the means of the TEM, SEM and x-ray diffraction technique, with the micro-hardness machine and universal tensile testing machine.Experimental study of the process of hot deforming 6016 aluminum alloy shows that: a dense substrate and a chain organization of the second phase is obtained in the hot rolled 6016 aluminum; a large amount of small angle boundaries form, but later transform to large angle boundaries, and recrystallization-nucleation occurs at some advantageous locations; recrystallization and grain growth are promoted by heat preservation; the binary microstructure of banded grains and gathered fine recrystallization grains forms at last; on the other hand, rolling texture dominated by Brass texture appears during hot deformation; with the deformation proceeding, Copper and random texture transform to Brass and S texture; Goss and other orientation grains form in S and Brass texture grains during the heat prevention procedure, leading to the reduction of the S and Brass texture strength.Experimental study of the process of 6016 aluminum alloy cold rolling shows that:with the increase of cold rolling passes, grains constantly elongate along the RD, also catenation of second phase particles are crushed; at the same time, a large amount of small angle boundaries form, and appears an angle about 40° to the RD during low and medium strains; in the initial rolling stage, overall coordinate deformation and rotation of grains make deformation texture occurs, and in further deformation, areas near the grain boundary is easy to rotate from grain’s initial orientation to the β orientation line and the interior area of grains at last. It is trough the two mechanisms that the deformation textures, led by S texture, forms and constantly increase.The study on the cold rolled sheet of solid solution treatment and aging treatment shows that: Recrystallization and solid solution procedure are taken place simultaneously, but the speed of recrystallization is faster than solution;Recrystallization forms fine, uniform and equiaxial grains in 90 s under 540℃ condition and Mg2 Si completely dissolved in 300 s, but the surplus silicon phase and indissolvableslag inclusions are preserved; During the solid solution, rolling texture mainly transforms to random texture and the majority texture of S and Copper quickly decrease.But Cube and R texture gradually increase, becoming the main texture.The highest hardness of 6016 aluminum alloy can be acquired by aging 4h at 180℃.The bake hardenability of T4 P stage is better than that of T4 and S stage. Especially the alloy at the T4P5 stage can reach to high hardness only 15 min of baking. Among the T4 stage, the T4P5 stage and the T6 stage, the different aging precipitation behavior makes the r value of the T4P5 stage higher than that both of the T4 and T6 stage. So,immediate pre-aging of 170℃×5min after solid solution, not only can the better bake hardenability be gained, but also can formability be improved.