【作者】 吴海飞； 徐金富； 费有静； 陈胜； 张学彬； 叶以富；

【Author】 WU Hai-fei~1 XU Jin-fu~(1,2) FEI You-jing~3 CHENG Sheng~1 ZHANG Xue-bin~3 YE Yi-fu~1 (1.Institute of Materials Science and Engineering,East China University of Science and Technology,Shanghai 200237,China; 2.Ningbo Institute of Engineering,Ningbo 315016,China; 3.Institute of Materials Science and Engineering,China University of Mining and Technology,Xuzhou 22100,China)

【机构】 华东理工大学材料科学与工程学院； 中国矿业大学材料科学与工程学院；

【摘要】 用放电等离子烧结法（SPS）制备了不同增强相的 MoSi₂基复合材料,系统研究了第二相对 MoSi₂基复合材料组织与性能的影响,探讨了 MoSi₂基复合材料的断裂方式及增韧机制。结果表明：第二相颗粒的加入均能不同程度地提高 MoSi₂的强韧性；ZrO₂对提高断裂韧性最有效,其中20%ZrO₂/MoSi₂材料达到6．8Mpam^1/2,比纯 MoSi₂提高了95．4%,表现为微裂纹增韧和弥散强化；β-Si₃N₄对提高显微硬度、抗压强度最有效,其中20%β-Si₃N₄/MoSi₂分别达到16．01Gpa 与2260Mpa,比纯 MoSi₂ 提高了31．7%与119．4%,表现为细晶强化；同时加入 ZrO₂与β-Si₃N₄能起到相变增韧和细晶强化的协同作用,表现出最佳的强韧性能,其中,10%ZrO₂/20%β-Si₃N₄/MoSi₂的维氏硬度、抗压强度、断裂韧性分别比 MoSi₂提高了24．7%、104．3%、90%。更多还原

【Abstract】 MoSi₂ matrix composites with different strengthen phases were prepared by the spark plasma sintering（SPS）technique,the influence of second phase on the microstructure and mechanical properties of MoSi₂ matrix composites were systematically studied,and the fracture mechanics and toughening mechanism of MoSi₂ matrix composites also be investigated.The results show that compared with MoSi₂ monomer,the hardness,compression strength,fracture toughness of 10%ZRO₂/20% β-Si₃N₄/MoSi₂ composite increase by 24.7%,104.3%,90% respectively;Furthermore,dispersion strengthening and microcrack toughening are the major toughening mechanism of ZrO₂/MoSi₂ composite,fine-grained strengthening is the toughening mechanism of β-Si₃N₄/MoSi₂ composite,and the ZrO₂/β-Si₃N₄/MoSi₂ composite is the effect of transformation toughening and fine-grained strengthening.更多还原