Microstructures and properties of ultrafine grained W–ZrC composites

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>The microstructures and properties of W–ZrC composites prepared in situ were compared with those of conventionally prepared W–ZrC and W–(Zr, W)C. In situ preparation led to an ultrafine microstructure with a homogeneous dispersion of ZrC, while the other composites showed microstructures similar to each other. The composite of W containing 30vol.% (Zr<SUB>0.88</SUB>W<SUB>0.12</SUB>)C showed an excellent flexural strength of ∼1425MPa at 1000°C. It also showed an excellent flexural strain of 0.051 at 1400°C, which was obtained by using a maximum displacement of 2.41mm. Those values have never been reported previously. A similar W composite, in situ W–10vol.% ZrC, demonstrated a flexural strength of 1324MPa and a displacement of 0.9mm under similar conditions. The results of this study are discussed in terms of microstructure and phase stability.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Various W–<I>x </I>vol.% ZrC (C), (I), and (S) (<I>x </I>=10 or 30) samples were prepared. </LI> <LI> W–ZrC (I) revealed homogeneously dispersed ultrafine grained microstructures. </LI> <LI> W–ZrC (S) showed a mixed form with microstructural features of W–ZrC (C) and (I). </LI> <LI> The W–ZrC (I) and (S) samples were stronger and more ductile than W–ZrC (C). </LI> <LI> The flexural strength of ∼1425MPa at 1000°C was shown by W–30 vol.% (Zr, W)C (S). </LI> </UL> </P>