(1. 东华大学 机械工程学院，上海 201620；2. 东华大学 纺织装备教育部工程研究中心，上海 201620；
3. 东华大学 材料科学与工程学院，上海 201620)
摘 要: 以高能球磨法制备的WC-MgO复合粉末为原料，研究稀土氧化物(La2O3)添加量对WC-MgO复合粉末热压烧结块体的组织和力学性能的影响，采用XRD、SEM和SPM对复合材料的结构特征进行表征，并讨论稀土氧化物(La2O3)对颗粒增韧复合材料热压烧结成形的影响。结果表明：La2O3的加入量为0.1%(质量分数)，可抑制烧结过程中出现的脱碳现象、细化烧结组织，提高增韧颗粒分散均匀性和改善颗粒/基体界面形貌，使成形致密度达理论密度的98.56%，维氏硬度和断裂韧性分别为18.02 GPa与12.38 MPa∙m1/2；而添加过量La2O3(≥0.25%，质量分数)，导致复合材料的成形性能降低。
关键字: WC-MgO；La2O3；热压烧结；显微组织；力学性能
of hot-pressing sintered WC-MgO composite material
（1. College of Mechanical Engineering, Donghua University, Shanghai 201620, China;
2. Engineering Research Center of Advanced Textile Machinery,
Ministry of Education, Donghua University, Shanghai 201620, China;
3. College of Materials Science and Engineering, Donghua University, Shanghai 201620, China）
Abstract:The WC-MgO composite powder synthesized by high-energy ball milling was used as raw material. A detailed investigation was carried out into the influence of rare earth (RE) oxide (La2O3) contents on the microstructure and mechanical properties of the as-consolidated WC-MgO bulk composites prepared by hot-pressing sintering method (HPS). The effective mechanisms of rare earth material (La2O3) in hot-pressing sintered composite were discussed. The results show that, by addition of 0.1% La2O3, the sintered structure can be refined, the decarburization reaction can be suppressed, the reinforcing particulates can be homogeneously refined, and the particulate and matrix bonding can be improved, leading to a high relative density of 98.56%, while the hardness is 18.02 GPa and the fracture toughness is 12.38 MPa∙m1/2. However, an excessive addition of La2O3 (≥0.25%) results in the decrease of the hot-pressing sintering ability.
Key words: WC-MgO; La2O3; hot-pressing sintering; microstructure; mechanical properties
