Influence of Al2O3 Particles Weight Fraction on Fracture Mechanism of AZ61 Mg-Al2O3 System Studied by In Situ Tensile Test in SEM

M. Besterci a, Š. Nagyb,c, S.-J. Huang d, O. Velgosováe, K. Sülleiová a and P.-C. Lin d aInstitute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 040 01 Košice, Slovakia bInstitute of Materials and Machine Mechanics, Slovak Academy of Sciences, Račianska 75, 831 02 Bratislava, Slovakia cInstitute of Materials Science, Faculty of Material Sciences and Technology in Trnava, Slovak University of Technology in Bratislava, Slovakia dNational Taiwan University of Science and Technology, Department of Mechanical Engineering, 43, Sec. 4, Keelung Rd., 106 Taipei, Taiwan, R.O.C. eDepartment of Materials Science, Faculty of Metallurgy, Technical University in Košice, Park Komenského 11, 042 00 Košice, Slovakia

Received: April 16, 2015; In final form: July 21, 2015

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In situ observation of AZ61 Mg alloy with 1 and 5 wt% of Al2O3 in the scanning electron microscopy was performed to study influence of the weight fraction of Al2O3 particles on the deformation and fracture mechanism during tensile test. Structure of the experimental materials was also analysed; microstructures were heterogeneous, with randomly distributed globular Al2O3 particles (average diameter of 25 nm) and Mg17Al12 intermetallic phase (average diameter of 0.4 μ m). It was shown that during tensile deformation the failure of Mg17Al12 particles and decohesion of the matrix-Al2O3 particles interphase boundary started simultaneously. Decohesion resulted from the different physical properties of matrix and Al2O3 particles. The influence of the Al2O3 weight fraction on the final fracture was evident; for material with 5 wt% of Al2O3, the fracture surface was approximately perpendicular to the loading direction and for material with 1 wt% of Al2O3 was at 45° angle. Fracture surface had transcrystalline ductile character.

DOI: 10.12693/APhysPolA.129.138 PACS numbers: 81.05.-t, 62.20.mm, 62.23.Pq