Finite element simulation and experimental investigation on the mechanical properties of nanostructured/ultra-fine grained Al-Mg-Si alloyproduced by equal channel angular pressing

The mechanical properties and the microstructure of the nanostructured/ultra-fine grained Al-Mg-Si alloy produced by severe plastic deformation were investigated. Equal channel angular pressing (ECAP) method was implemented in order to induce large plastic strain to the billets and to produce nanostructured/ultra-finegrained material. The Vickers microhardness measurements showed that the increase in the microhardness ofthe bottom region of the billet was relatively low. Also, the numerical simulation of the ECAP process usingDEFORM-3D software was used to verify the amount of the increase of microhardness value during the process. Furthermore, Simple tensile test which was conducted to investigate the mechanical behavior of theprocessed materials showed that both the yield strength and the ultimate strength of the alloy increased morethan 80%. However, this increase was followed by slight decrease in the ductility of the material. Assessment of the fracture surfaces of the samples showed that the large and deep dimples corresponding to the high elongation of the annealed sample were replaced by small, well developed and uniformly distributed dimples after two ECAP passes. In addition, further increase in the number of ECAP passes caused the formation of parabolic shaped micro-voids indicating the shear type fracture mode in the uni-axial tensile test

Keywords:

Equal channel angular pressing , mechanical properties , microhardness , severe plastic deformation , X-ray diffraction