CNTs的添加对纳米Si3N4陶瓷组织与力学性能的影响
Effect of CNTs on Microstructure and Mechanical Properties of Si3N4 Nano-ceramic
田春艳1, 姜 海1, 刘 宁2
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作者单位：(1. 合肥学院 机械工程系, 安徽 合肥 230022; 2. 合肥工业大学 材料科学与工程学院, 安徽 合肥 230009)
中文关键字：Si3N4； 碳纳米管； 纳米复相陶瓷；力学性能； 韧化机理
英文关键字：Si3N4; carbon nano-tubes; nano-composite ceramic; mechanical properties; toughening mechanism
中文摘要：采用热压烧结法制备了CNTs-Si3N4纳米复相陶瓷，研究了碳纳米管(CNTs)的添加对Si3N4陶瓷组织与力学性能的影响，用XRD分析了该复合材料的相组成，并对它的硬度、抗弯强度和断裂韧性进行了测试。结果表明，CNTs-Si3N4纳米复相陶瓷的相为α-Si3N4、β-Si3N4和Si2N2O；其抗弯强度和断裂韧性均随碳纳米管含量的增加呈先升后降的变化趋势， 最大值分别在CNTs添加量为2wt%和4wt%时获得； CNTs添加量为2wt%时，硬度略有提高，然后随碳纳米管含量的继续增加而逐渐降低；CNTs-Si3N4纳米复相陶瓷的主要增韧机制为碳纳米管的拔出、桥联和裂纹偏转。
英文摘要：CNTs-Si3N4 nano-composite ceramic was fabricated by hot press sintering. The effects of CNTs on the microstructure and mechanical properties of Si3N4 nano-ceramics were investigated. The phase composition of the compound ceramic was investigated by XRD. The hardness, bending strength and fracture toughness of the compound ceramic was measured. The results show that the main phases in CNTs-Si3N4 nano-composite ceramic are α-Si3N4, β-Si3N4 and Si2N2O. The fracture toughness and flexural strength firstly increase with the increase of carbon nano-tube content and then decrease,and the maximum fracture toughness and flexural strength are obtained when the content of carbon nano-tube is 4wt% and 2wt%, respectively. The hardness has a little increase when the amount of carbon nano-tubes is 2wt%, then gradually decreases with the increase of carbon nano-tube content. The main toughening mechanism of CNTs-Si3N4 nano-composite ceramics is the extraction of CNTs, the bridging of CNTs and crack deflection.