Effects of consolidation conditions on microstructures and properties of tungsten-vanadium alloy

Abstract

To face the harsh environment of intense irradiations, tungsten vanadium alloys (W-5wt.% V) were fabricated by spark plasma sintering (SPS) of mechanical alloying powder under different consolidation conditions. X-ray diffraction (XRD) was used to study the phase structures of the alloy powder and the sintered material. To investigate the improvements in mechanical properties and microstructures, the sintering temperatures and dwell times were taken into account for similar composition of tungsten vanadium alloy. The mechanical properties were estimated using micro-hardness and bending strain tests. The detail morphology analysis of the polished cross sectional surface and fracture surface of the samples were performed by scanning electron microscopy (SEM) and quadrant back scattering detector (QBSD). A highest relative density was achieved by alloy material sintered at 1600 °C for 5 min. The two alloy specimens, one sintered at 1100 °C for 2 min and then at 1600 °C for 3 min and the other sintered at 1600 °C for 3 min, have relatively low density but show better mechanical properties. The grain growth of tungsten and vanadium was influenced by consolidation temperature and not much by the difference in dwell time at same peak temperature.