Research on microstructures and properties of W-Lu2O3 composite strengthened with Nb and C trace elements

Abstract:

W-Lu₂O₃ and W-Nb-C-Lu₂O₃ composites were fabricated by mechanical milling and spark plasma sintering. The morphology of composite powders, surface and fracture surface morphology of the samples were characterized by field-emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The relative density, thermal conductivity, hardness and strength of the samples were also measured. Results revealed that the addition of trace Nb and C on the basis of W-Lu₂O₃ composite had an obvious effect on grain refinement, densification and strength. The relative density of W-Nb-C-Lu₂O₃ composite was 5.75% higher than W-Lu₂O₃ and reached 95.12%. The grain size of W-Nb-C-Lu₂O₃ composite was refined from 8~13 μm to 2~5 μm, and its microhardness and strength were obvious improved compared with W-Lu₂O₃ composite.