添加剂CeO_2对WC-Al_2O_3复合材料微观组织和力学性能的影响

Effects of CeO_2 additives on the microstructure and mechanical properties of WC-Al_2O_3 composites

为了进一步提高WC-Al2O3复合材料的力学性能,研究少量添加剂CeO2对热压烧结WC-Al2O3复合材料的影响。研究结果表明,在WC-Al2O3复合材料中添加0.1%CeO2后,与不含添加剂相比,组织细化且力学性能有所提高;少量添加剂CeO2具有抑制WC氧化脱碳、细化晶粒、改善基体WC和第二相Al2O3颗粒之间界面结合状况的作用。WC-Al2O3-0.1%CeO2复合材料的致密度达到98.82%,维氏硬度、断裂韧性和抗弯强度分别达到16.89GPa、9.85MPa·m1/2和1024.05MPa。

To improve the mechanical properties of WC-Al2O3 composites,the effects of trace amount of CeO2 additives on the microstructure and mechanical properties of the WC-Al2O3 composites prepared by hot pressing were investigated. The results showed that the WC-Al2O3 composites doped with 0. 1% CeO2 possessed the refined microstructure and enhanced mechanical properties compared with that of the undoped WC-Al2O3 composites. Trace CeO2 suppressed the decarburization of WC, promoted the microstructural refinement and improved the interface coherence of the WC matrix and Al2O3. When 0. 1% CeO2 were added to the WC-Al2O3 composites,the effect of CeO2 resulted in the achievement of a relative density of 98. 82% with an excellent Vickers hardness of 16. 89 GPa,combining a fracture toughness of 9. 85 MPa · m1 /2with an acceptable flexural strength of 1 024. 05 MPa.