Premium
High‐Strength B 4 C–TaB 2 Eutectic Composites Obtained via In Situ by Spark Plasma Sintering
Author(s) -
Demirskyi Dmytro,
Sakka Yoshio,
Vasylkiv Oleg
Publication year - 2016
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.14235
Subject(s) - materials science , eutectic system , flexural strength , composite material , spark plasma sintering , ceramic , boron carbide , vickers hardness test , indentation , ceramic matrix composite , brittleness , fracture toughness , sintering , cubic zirconia , microstructure
The in situ synthesis/consolidation of B 4 C–TaB 2 eutectic composites by spark plasma sintering ( SPS ) is reported. Samples for the evaluation of bending strength were cut from specimens with diameters of 30 mm. The sample prepared for the three‐point flexural strength test had fibers of tantalum diboride with diameter of 1.3 ± 0.4 μm distributed in the B 4 C matrix, thereby reducing composites brittleness and yielding an indentation fracture toughness of up to 4.5 MPa·m 1/2 . Furthermore, the Vickers hardness of B 4 C–TaB 2 eutectics formed by SPS was as high as 26 GPa at an indentation load of 9.8 N. The flexural strength of the B 4 C–TaB 2 system has been reported for the first time. Some steps were identified in the load–displacement curve, suggesting that micro‐ and macrocracking occurred during the flexural test. Ceramic composites with a eutectic structure exhibited a room‐temperature strength of 430 ± 25 MPa. Compared with other eutectic composites of boron carbide with transition‐metal diborides, room‐temperature strength the B 4 C–TaB 2 was 40% higher than that of B 4 C–TiB 2 ceramics, demonstrating advantage of the in situ synthesis/consolidation of eutectic composites by SPS .