Structure, hardness and fracture toughness of arc-melted LaB6-TiB2 eutectic alloy

Fourth interdisciplinary scientific forum with international participation "New materials and promising technologies"

Nesmelov, D.D.^1 ; Vikhman, S.V.^1 ; Novoselov, E.S.^1 ; Perevislov, S.N.^2 ; Ordan'Yan, S.S.^1

Saint-Petersburg State Institute of Technology, Saint-Petersburg, Russia^1

Institute of Silicate Chemistry of Russian Academy of Sciences, Saint Petersburg, Russia^2

关键词: Electric arc melting;    Eutectic alloys;    Eutectic composites;    Floating zones;    Median diameters;    Micro-structural;    Monocrystalline;    SEM micrographs;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/525/1/012066/pdf
DOI  :  10.1088/1757-899X/525/1/012066

来源: IOP

【 摘 要 】

Microstructural and indentation-Techniques mechanical investigations have been performed on a LaB6-TiB2 eutectic composite, obtained by the electric arc-melting in argon flow. Structure of solidified eutectics consists of directionally crystallized TiB2 fibers in LaB6 matrix. XRD, SEM and EDX analysis of eutectics were performed. The median diameter of the TiB2 fibers, calculated using statistical analysis of SEM micrographs, was 0.45 μm. The volume fraction of the TiB2 phase in eutectics was 16% as calculated by area fractions from SEM micrographs. The Vickers hardness (25.5 GPa) and fracture toughness (6.7 MPa ⋅m1/2) were measured on arc-melted LaB6-TiB2 alloy. Results were compared with the same ones, measured on floating-zone melted monocrystalline LaB6.