Tensile Properties and Tensile Fracture Characteristics of Cast Al-Zn-Mg Alloys Processed by Equal Channel Angular Pressing

摘要

In the present work, as-cast Al-5Zn-2Mg, Al-10Zn-2Mg and Al-15Zn-2Mg alloys were ECAP processed and tensile tests were carried out to determine the strength and ductility. After tensile testing, morphology of the fracture surfaces of tensile tested samples were studied. After ECAP processing, significant improvement in the yield stress and ultimate tensile strength were observed in all the three alloys. Also, yield stress and ultimate tensile strength were increased with increase in the zinc content of the material. The elongation to failure increased significantly with increase in the number of ECAP passes. SEM micrographs revealed that, the fracture surface of the cast samples of the alloys were composed of the dendritic structure, while the ECAP processed samples consisted of small size dimples. Size of the dimples were reduced with the increase in the number of ECAP passes.