(1. 東華大學 機械工程學院，上海 201620；2. 東華大學 紡織裝備教育部工程研究中心，上海 201620；
3. 東華大學 材料科學與工程學院，上海 201620)
摘 要: 以高能球磨法制備的WC-MgO復合粉末為原料，研究稀土氧化物(La2O3)添加量對WC-MgO復合粉末熱壓燒結(jié)塊體的組織和力學性能的影響，采用XRD、SEM和SPM對復合材料的結(jié)構(gòu)特征進行表征，并討論稀土氧化物(La2O3)對顆粒增韌復合材料熱壓燒結(jié)成形的影響。結(jié)果表明：La2O3的加入量為0.1%(質(zhì)量分數(shù))，可抑制燒結(jié)過程中出現(xiàn)的脫碳現(xiàn)象、細化燒結(jié)組織，提高增韌顆粒分散均勻性和改善顆粒/基體界面形貌，使成形致密度達理論密度的98.56%，維氏硬度和斷裂韌性分別為18.02 GPa與12.38 MPa∙m1/2；而添加過量La2O3(≥0.25%，質(zhì)量分數(shù))，導致復合材料的成形性能降低。
關鍵字: WC-MgO；La2O3；熱壓燒結(jié)；顯微組織；力學性能
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
