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.% (Zr-0.88 W-0.12) C showed an excellent flexural strength of similar to 1425 MPa at 1000 degrees C. It also showed an excellent flexural strain of 0.051 at 1400 degrees 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. (C) 2014 Elsevier B.V. All rights reserved.