微量元素Nb、C强化W-Lu2O3复合材料的组织及性能研究

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

摘要:

采用机械球磨和放电等离子体烧结制备了W-Lu₂O₃和W-Nb-C-Lu₂O₃合金,通过场发射扫描电子显微镜(FE-SEM)、能谱(EDS)和透射电子显微镜(TEM)研究分析了合金复合粉末的形貌、合金烧结体表面形貌和断口形貌；测定了合金的致密度、热导率、硬度和强度。实验结果表明：在W-Lu₂O₃的基础上添加微量Nb和C对钨合金晶粒细化、致密化和强度提高有着明显的效果,W-Nb-C-Lu₂O₃合金的致密度比W-Lu₂O₃提高了5.75%,达到了95.12%,晶粒尺寸由8~13 μm细化到2~5 μm,W-Nb-C-Lu₂O₃合金比W-Lu₂O₃合金的显微硬度和强度得到明显改善。

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.