无机材料学报

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纳米/微米CaB6烧结体的形貌组织和力学性能

张 琳1,2, 闵光辉1, 于化顺1   

  1. (山东大学 1. 材料液固结构演变与加工教育部重点实验室; 2.机械工程博士后科研流动站, 济南 250061)
  • 收稿日期:2009-04-27 修回日期:2009-06-30 出版日期:2010-01-24 网络出版日期:2010-01-24

Morphology Characteristics and Mechanical Properties of Nano/Micron Calcium Hexaboride Sintered Body

ZHANG Lin1,2, MIN Guang-Hui1, YU Hua-Shun1   

  1. (1. Key Laboratory for LiquidSolid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061, China; 2. Mechanical Engineering Postdoctoral Research Station, Shandong University, Jinan250061, China)

  • Received:2009-04-27 Revised:2009-06-30 Published:2010-01-24 Online:2010-01-24

摘要:

采用真空热压工艺, 在烧结温度1750℃、烧结压力32MPa、保温时间5min的工艺条件下制备了添加不同量纳米六硼化钙(CaB6)粉末的微米烧结体, 研究了纳米粒子含量对CaB6烧结体形貌组织和力学性能的影响. 纳米粉末加入量为10wt%纳米/微米复合陶瓷的致密度和力学性能最佳, 硬度、弯曲强度和断裂韧性分别为92.6 HRA、331.7MPa和3.06MPa·m1/2, 优于微米烧结体和添加镍作为烧结助剂的烧结体. 纳米粒子对微米颗粒晶界的填充和在复合烧结体中形成的“内晶型”晶粒结构是提高复合陶瓷致密度和力学性能的主要原因.

关键词: 六硼化钙, 纳米/微米复合陶瓷, 真空热压烧结, 内晶型, 力学性能

Abstract:

Nano/Micron Calcium Hexaboride (CaB6) composite ceramics with different CaB6 nanopowder additions were prepared under 1750℃, 32MPa for 5min in vacuum. Influences of CaB6 nanopowders on morphology and mechanical properties of sintered bodies were investigated. Composite ceramic with 10wt% CaB6 nanopowder addition has the highest compactness degree and mechanical properties, whose hardness, bending strength and fractural toughness are 92.6 HRA, 331.7MPa and 3.06MPa·m1/2, respectively, better than those of CaB6 ceramics without nanopowder adding or those of reinforced by Ni as sintering additive. The proper amount of nano-particles filled in the micron grain boundaries and the formation of “inner crystal” result in the improvement of compactness and mechanical properties for the CaB6 sintered body.

Key words: calcium hexaboride, nano/micron composite ceramic, vacuum hot-pressing, intragranular structure, mechanical property

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