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Phasenanalyse und Phaseneinfluss auf die Bruchmechanik von AZ61‐SiC‐Verbundwerkstoff
Author(s) -
Besterci M.,
Sulleiova K.,
Ballokova B.,
Nagy S.,
Velgosova O.,
Huang S.J.
Publication year - 2019
Publication title -
materialwissenschaft und werkstofftechnik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.285
H-Index - 38
eISSN - 1521-4052
pISSN - 0933-5137
DOI - 10.1002/mawe.201800123
Subject(s) - materials science , ultimate tensile strength , silicon carbide , composite material , brittleness , coalescence (physics) , composite number , scanning electron microscope , microstructure , magnesium , tensile testing , metallurgy , physics , astrobiology
Phase composition of AZ61‐SiC composite with 5 wt.% of nanosized silicon carbide reinforcement was analysed and failure mechanism by in situ tensile test in scanning electron microscope was observed. Microstructure of the experimental materials was heterogeneous with grain size of 15 μm. Based on the quantitative analysis of composite, besides, silicon carbide strengthened particles added externally into the matrix magnesium silicide, magnesium oxide, and aluminium/manganese particles formed in situ were found in the matrix. In situ tensile test in scanning electron microscope has shown that reinforcing particles substantially influenced failure mechanism. Large, brittle magnesium silicide particles (size of 40 μm–50 μm) cracked during tensile deformation and at the same time, as a result of different physical properties, decohesion of the matrix and smaller aluminium/manganese, silicon carbide and magnesium oxide particles (size of 5 μm–10 μm, 10 μm and 50 nm respectively) occurred. Reinforcing particles and brittle secondary phases driven micro voids and their coalescence was found as a major cause of large cracks formation. Subsequently the increase of stress caused the cracks propagation by the coalescence of fractured particles and decohesively release smaller dispersed particles. The fracture propagated at approximately 90° angle to the direction of the tensile load direction. Fracture surface had feature of transcrystalline and intercrystalline failure.