Study On Microstructure And Mechanical Properties Of Aluminum 1060 Fabricated By Multi-Layer Accumulative Roll Bonding

Accumulative roll bonding(ARB)is one of the most promising and cost-effective severe plastic deformation(SPD)process to continuous preparation of ultrafine metal plates.It is urgent and necessary to improve the process and achieve a good match of strength and plasticity in the material for preparing high-performance aluminum alloy by ARB process.In this paper,aluminum alloy with improved properties of aluminum alloy(M1),bimodal aluminum alloy(M2)and bimodal aluminum matrix composite(M3)samples were designed and prepared by the multi-layer accumulative roll bonding(MARB)process.The strength and elongation of the materials were improved by preparing bimodal structure and adding Si C particles.Through Optical microscopy(OM),Scanning electron microscopy(SEM),Electron backscatter diffraction(EBSD),tensile tests and hardness tests,the effect of structure improvement on the structure and properties of the prepared materials was studied,and the some points were obtained as follows:(1)M1 sample with tensile strength(TS)of 198.4 MPa and elongation of 13.5% was prepared.M2 sample with TS of 200.9 MPa and elongation of 13.5% was prepared.M3 sample with TS of 225 MPa and elongation of 13% was prepared.The structural design of bimodal structure and metal matrix composites could improve the overall mechanical properties of the materials.(2)After MARB process,the new bonding interface of mechanical bonding rapidly tends to form metallurgical bonding.Especially,the bonding strength of M3 sample was improved.After three cycles,Si C powders were basically uniformly distributed in the aluminum matrix,and the bonding state was well.After four cycles,Si C powders were completely uniformly distributed in the aluminum matrix.(3)MARB process could control grain size through intermediate annealing.After three cycles,the average grain size(AGS)in the normal direction of the annealed plate in M1,M2 and M3 is 0.92μm、1.15μm and 1.07μm,respectively.The AGS of one-passed plate in M2 and M3 is 0.46μm and 0.48μm,respectively.(4)After three MARB cycles,the texture components of M1 sample were Brass {011} <211>,S {123} <634> and Cube {001} <100>.The texture components of M2 sample were Brass {011} <211>,S {123} <634>,Copper {112} <111> and Goss {011} <100>.The texture components of M3 sample were S {123} <634>,Brass {011} <211>,Cube {001}<100>and Copper {112} <111>.The recrystallization mechanism of M1 and M3 sample was particle-stimulated nucleation effect.The recrystallization mechanism of M2 sample was nucleation at the shear bands.(5)The strengthening mechanism of M1 and M2 samples was mainly strain hardening and grain refining.The strengthening mechanism of M3 sample was strain hardening,grain refining and dispersion strengthening.With the increasing of passes,the TS of all samples showed an upward trend.With the increase of the layers,the increase of the number of bonding interfaces caused a limited reduction in TS.(6)All samples were ductile fracture,and the morphology of M1 and M2 was mainly shear lip and equiaxed dimple.M1 sample was characterized by hemispherical equiaxed dimple,and M2 sample was characterized by honeycomb dimple.The morphology of M3 sample was mainly shear lip,circular micropore and acicular dimple.