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Dense and core‐rim structured B 4 C‐TiB 2 ceramics with Mo‐Co‐WC additive
Author(s) -
Tan DaWang,
Lao ZhenYong,
Zhang Zhan,
Guo WeiMing,
Sun ShiKuan,
Lin HuaTay
Publication year - 2021
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.17657
Subject(s) - materials science , spark plasma sintering , sintering , fracture toughness , grain boundary , ceramic , phase (matter) , vickers hardness test , dissolution , metallurgy , composite material , microstructure , chemical engineering , chemistry , organic chemistry , engineering
B 4 C‐TiB 2 ceramics (TiB 2 ranging 5~70 vol%) with Mo‐Co‐WC as the sintering additive were prepared by spark plasma sintering. In comparison with B 4 C‐TiB 2 without additive, the enhanced densification was evident in the sintered specimen with Mo‐Co‐WC additive. Core‐rim structured grain was observed around TiB 2 grains. The interface of the rim between TiB 2 and B 4 C phases demonstrated different feature: the inner borderline of the rim exhibited a smooth feature, whereas a sharp curved grain boundary was observed between the rim and the B 4 C grain. The formation mechanism is discussed: the epitaxial growth of (Ti,Mo,W)B 2 rim around the TiB 2 core may occur as a result of the solid solution and dissolution‐precipitation between TiB 2 phase and the sintering additive. It was revealed that the fracture toughness increased as the content of TiB 2 content increased, alongside the decreased hardness. B 4 C‐30 vol% TiB 2 specimen demonstrated the optimal combination of mechanical properties, reaching Vickers hardness of 24.3 GPa and fracture toughness of 3.33 MPa·m 1/2 .