Effects of Equal Channel Angular Pressing (ECAP) Process with an Additional Expansion-Extrusion Stage on Microstructure and Mechanical Properties of Mg–9Al–1Zn

الموضوعات :

Mahnoush Rassa ¹ (Department of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran)
Geonik Azadkoli ² (Department of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran)
Mohammad Eftekhari ³ (Department of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran)
Ali Fata ⁴ (Department of Mechanical Engineering, Faculty of Engineering, University of Hormozgan, Bandar Abbas, Iran)
Ghader Faraji ⁵ (Department of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran)

تاريخ الإرسال : 18 الأربعاء , ذو الحجة, 1442 تاريخ التأكيد : 28 الأحد , محرم, 1443 تاريخ الإصدار : 26 الإثنين , ربيع الأول, 1443

الکلمات المفتاحية: Severe Plastic Deformation, EECAP, Ultrafine grained metals, AZ91 alloy,

ملخص المقالة :

In this study, equal channel angular pressing (ECAP) process with an additional expansion-extrusion stage named expansion-extrusion equal channel angular pressing (EECAP) process is utilized for producing bulk ultrafine grained (UFG) Mg–9Al–1Zn magnesium alloy. In this process, cyclic expansion-extrusion (CEE) and equal channel angular pressing (ECAP) processes are combined. AZ91 magnesium alloy was used for this experiment. An FEM simulation was performed to calculate the compressive hydrostatical stress. Furthermore, microstructural and mechanical properties were investigated. The experimental findings revealed that the ductility of the sample remains almost constant (0.03% drop) while ultimate tensile strength increased about 30%. The average value of microhardness improved from 48 Hv to 65 Hv (35%) and grain size refined from 144 µm to 3.4 µm. Despite the expansion part of the die, there is no need for back pressure. Another advantage of this new method is maintaining ductility while strengthening.

المصادر:

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