The Research On Refining Rules And Properties Of Severe Plastic Deformation 6016 Aluminum Alloy

To achieve weight reduction of the automotive is a more effective way to save energy.The automotive parts made of aluminum instead of steel so that it can reduce the vehicle weight in large numbers.Then it can realize the energy conservation and emissions reduction.6000 aluminum alloy series grain refinement is important to improve the plastic formability and strength.In this paper,6016 aluminum alloy ECAP experiments and friction stir processing experiments are carried out.It studied the cold deformation process of grain refinement and the texture change by observing optical microscopy,EBSD orientation mapping technology and thermal simulation compression experiment.The samples were annealed after ECAP extrusion,and the influences of annealing temperature as well as annealing time on grain size have been studied.After friction stir processing fine grain microstructure Fine-grained microstructure after friction stir processing was annealed.In order to study the thermal stability of fine-grained microstructure.After ECAP extrusion,the grain structure of 6016 aluminum alloy changed.On the X plane the shape and size of the grain almost not change,while on the Z plane the grain was stretched.Extrued texture dominated by Brass texture and rotating cube texture.Hardness method research results show that the deformations of sample in head and tail are extremely inhomogeneous,the deformation at the top is similar with the top and the middle,and the deformation at the bottom was very different with the top and the middle.SO the hardness of the bottom changed greatly.The recrystallization temperature of one pass ECAP 6016 aluminum alloy was between 260?-280?.Annealing temperature has a great influence on the microstructure and hardness of ECAP cold deformation,which is possitive to the grain refinement.After annealing the sample hardness decreased with annealing temperature increased.While the FSP 6016 aluminum alloy mixing head rotational speed is 800r/min,and the forward speed is 100mm/min,6016 aluminum alloy didn't have obvious cosmetic defects such as cracks.It indicated that the method can improve material processing performance and increase alloy mechanical properties significantly.After friction stir processing,the microstructure of 6016 aluminum alloy was dynamically crystallized,the grain was refined significantly,and stirring zone grains are fine equiaxed grain structure.The texture intensity is very weak,and the orientation is not concentrated.Themixing zone fine grains have good thermal stability,as well as doesn't have recrystallization and regrowth at higher temperature,and they are still fine grain organization.The hot compression simulation experiment of 6016 aluminum was carried out,and the yield strength,strain rate sensitivity index m and strain rate curves were analyzed.Making the flow stress and strain rate under different temperature according to the obtained data.The stress-strain behavior of the alloy in warm plastic deformation was analyzed,and it showed that the flow stress is decreasing with increasing temperature and strain rate.The constitutive equation of the temperature compressive plastic deformation of 6016 aluminum alloy was obtained as well as the value of the theoretical yield limit.