超硬的纳米双胞胎立方化
Yongjun Tian1, Bo Xu, Dongli Yu
1State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China.
Nature
|January 18, 2013
概括
研究人员开发了具有特殊硬度和性的纳米双胞胎立方化 (cBN). 这种先进的cBN材料在硬度上超过了合成钻石,并为工业应用提供了卓越的性能.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
- 超硬材料 超硬材料
背景情况:
- 立方化 (cBN) 是一种具有重要的工业应用的超硬材料.
- 纳米结构cBN通过Hall-Petch效应提高硬度,其中较小的颗粒大小增加了硬度.
- 传统的合成方法产生多晶cBN,颗粒大小约为14nm.
研究的目的:
- 合成和表征一种具有增强机械性能的新型纳米结构cBN材料.
- 研究纳米结构,特别是双域厚度和cBN硬度之间的关系.
- 探索纳米双胞胎cBN在苛刻的工业应用中的潜力.
主要方法:
- 纳米双胞胎cBN的合成使用特别准备的BN前体纳米粒子与嵌套结构和状层.
- 纳米结构的表征,专注于双域厚度 (平均约3.8nm).
- 评估机械性能,包括维克尔硬度,氧化温度和断裂性.
主要成果:
- 形成光学透明的纳米双胞胎cBN批量样本.
- 达到了超过100GPa的维克尔硬度,超过了合成钻石.
- 经过证明的高氧化温度 (~1,294°C) 和破裂性 (>12 MPa·m^(1/2)).
- 观察到连续硬化与双胞胎厚度下降,偏离典型的霍尔-佩奇或反向霍尔-佩奇效应.
结论:
- 从嵌套的前体纳米粒子合成的纳米双胞胎cBN表现出优越的硬度和性.
- 观察到的硬化行为表明了与超细双域相关的新机制.
- 这种先进的cBN材料对要求极度硬度和耐久性的应用具有前景.
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