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Growth and Microstructure‐Dependent Hardness of Directionally Solidified WC –W 2 C Eutectoid Ceramics
Author(s) -
Chen WeiTing,
Meredith Caleb H.,
Dickey Elizabeth C.
Publication year - 2015
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.13561
Subject(s) - eutectic system , materials science , microstructure , lamellar structure , indentation , vickers hardness test , ceramic , knoop hardness test , composite material , indentation hardness , phase (matter) , metallurgy , chemistry , organic chemistry
Directionally solidified WC –W 2 C ceramics containing 40 at% carbon, corresponding to the WC –W 2 C eutectoid composition, were produced by laser surface melt processing. The resulting microstructures showed a lamellar‐type eutectic/eutectoid microstructure with the WC minor phase embedded in the W 2 C matrix phase. The interlamellar spacing (λ) in the eutectoid regions followed the relationship V λ 3.8 = constant, with the smallest spacing of 331 ± 36 nm achieved in the 3.24 mm/s processed sample. The indentation hardness increased with decreasing interlamellar spacing, and a Vickers indentation hardness of 28.5 GPa was achieved in the sample with the smallest interlamellar spacing. The directionally solidified WC –W 2 C materials show enhanced indentation mechanical properties in comparison to previously reported WC –Co composites and WC ‐based materials.