STUDY 0F MICROSTRUCTURE AND HARDNESS OF EQUAL CHANNEL ANGULAR EXTRUDED 7075AL ALLOYS
Keywords:
SPD, E-cap, Microstructure, TEMAbstract
In the present years, there has been an increasing interest in the production of ultra-grained materials for investigative purposes. The ultra-grained materials exhibit mechanical and physical properties of great interest, in particular their remarkable strength and toughness. This paper reports a study of microstructures of the ultra-grained produced through equal channel angular processing (EACP), pressed 10 times through the 120º die angle impart a higher strain were investigated using optical microscope. The average grain size obtained from the optical microscope was 300 – 400 hm but the microstructure of ECAP aluminium was not homogeneous. The Vickers micro-harness tester was used for measured hardness on the different location in the extruded sample with an applied load of 1N. The universal testing machine was used for measuring ultimate tensile strength and ductility of samples. Elimination of dendritic as-cast structure with reduction of porosities and deformation- induced homogenization by the effect of ECAP processing increased the ductility of the alloy. Attained experimental results indicate that multi-pass ECAE processing is very effective in improving the hardness of binary 7075Al alloy
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