Microstructures and properties of ultrafine grained W-ZrC composites

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 30 vol.% (Zr0.88W0.12)C showed an excellent flexural strength of ∼1425 MPa 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 2.41 mm. Those values have never been reported previously. A similar W composite, in situ W-10 vol.% ZrC, demonstrated a flexural strength of 1324 MPa and a displacement of 0.9 mm under similar conditions. The results of this study are discussed in terms of microstructure and phase stability.