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Strong ZrC ceramics at high temperatures with the addition of W
Author(s) -
Shen YiBo,
Wang XinGang,
Zhang GuoJun,
Xue JiaXiang,
Li Qiang,
Jiang DanYu
Publication year - 2019
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.16320
Subject(s) - microstructure , materials science , ceramic , homogeneous , impurity , grain size , carbon fibers , composite material , oxygen , solid solution , analytical chemistry (journal) , mineralogy , metallurgy , chemistry , thermodynamics , physics , organic chemistry , chromatography , composite number
Abstract The effect of W addition on densification, microstructure, and mechanical properties of ZrC ceramics was investigated. W reacted with carbon in ZrC to form WC, which resulted in the formation of ZrC 1‐x at 1300‐1700°C, while WC was further dissolved in ZrC to form a (Zr 1‐y W y )C 1‐x solid solution at 1800‐2000°C. The relative density of ZrC with 5 mol% W (ZW5, 96.8%) was markedly higher than that of pure ZrC (Z0, 94.8%). ZW5 exhibited a fine homogeneous microstructure with a grain size (2.6 ± 0.5 μm) much smaller than that of Z0 (10.9 ± 3.0 μm), while excess W addition (10 mol%) in ZrC adversely affected the densification and the microstructure. The flexure strength of Z0 was 446 ± 46 MPa at room temperature, which almost linearly decreased to 281 ± 10 MPa at 1800°C in a high‐purity flowing argon atmosphere. The flexure strength of ZW5 was 512 ± 40 MPa at room temperature, and had no degradation even up to 1800°C. The fine and homogeneous microstructure of ZW5 and the removal of oxygen impurity from the grain boundaries promoted the enhancement of high‐temperature mechanical properties.