Simulation And Experimental Study On Equal Channel Angular Pressing For Commercial Pure Aluminum Bar

The ECAP (Equal channel angular pressing) technology has been gradually concerned by scholars, it is a method which could refine grain structure effectively. This process does not change the cross-sectional area and the shape of sample, so it could make a large and uniformity deformation produced repeatedly at a low pressure. After the sample through the corner of the channel with a severe shear deformation, the grain is refined effectively and the mechanical properties of the material are improved significantly.In order to research the effect of routes and passes for ECAP on the mechanical properties and microstructure of large sized pure aluminum bar, the article analyzed the changing regularity of them for pure aluminum with finite element numerical simulation and experimental study, the sample was extruded by multi-passes ECAP in three routes. It also discussed the mechanism of grain refinement.It was not only revealed the deformation process of pure aluminum bar by research, but also the extrusion pressure, the distribution regularities of velocity, equivalent stress and strain. It analyzed the effect of extrusion passes and routes on the strength, elongation, hardness, grain size and shape. The results showed that the accumulated strain made a severe plastic deformation was produced by the sample with the increase of extrusion passes. The mechanical properties of material were improved significantly and the grain was refined effectively. Eventually, the grain morphology of pure aluminum was changed from original coarse grain to fine equiaxed grain. What’s more, the extrusion passes had an important influence on the uniformity of the grain size distribution. The extrusion effects in different routes were Bc>C>A. By comparison of the experimental and simulation results on the changes of average grain size for ECAP, the validity of simulation was further proved.