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Densification and Mechanical Properties of Spark Plasma Sintered B 4 C with Si as a Sintering Aid
Author(s) -
Ye Feng,
Hou Zhaoping,
Zhang Haijiao,
Liu Limeng
Publication year - 2010
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/j.1551-2916.2010.03931.x
Subject(s) - spark plasma sintering , materials science , fracture toughness , flexural strength , sintering , ceramic , vickers hardness test , composite material , thermal expansion , microstructure
B 4 C ceramics doped with different Si contents were fabricated by the spark plasma sintering technique. Pure B 4 C ceramic could be densified to 99% of the theoretical density. The sinterability could be further improved by the addition of a small amount of Si due to the formation of liquid Si during sintering. The incorporation of Si could also remarkably increase the mechanical properties of B 4 C ceramics. The Vickers hardness, flexural strength, and fracture toughness of the sample with 8 wt% Si could reach 41.8 GPa, 640 MPa, and 6.1 MPa·m 1/2 . The improvement in hardness and strength was attributed to grain refinement. Crack deflection due to the thermal expansion mismatch between the B 4 C and SiC was found to be the main toughening mechanism.