Structure, mechanical properties and thermal stability of CrAlN/ZrO2 nanomultilayers deposited by magnetron sputtering
Structure, mechanical properties and thermal stability of CrAlN/ZrO2 nanomultilayers deposited by magnetron sputtering
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DOI：
10.1016/j.jallcom.2013.02.020
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发表时间：
2013-06
影响因子：
6.2
通讯作者：
Wei Li;Ping Liu;Yongsheng Zhao;Fengcang Ma;Xin-kuan Liu;Xiaohong Chen;Daihua He
中科院分区：
文献类型：
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作者：
Wei Li;Ping Liu;Yongsheng Zhao;Fengcang Ma;Xin-kuan Liu;Xiaohong Chen;Daihua He
采用反应磁控溅射法制备了不同ZrO 2层厚的新型CrAlN/ZrO 2纳米多层膜。采用X射线衍射（XRD）、场发射扫描电子显微镜（FE-SEM）、高分辨率透射电子显微镜（HRTEM）和纳米压痕技术研究了材料的结构、力学性能和热稳定性。结果表明，当ZrO 2层厚度小于1.0nm时，四方结构的ZrO 2层在CrAlN层的模板作用下被迫转变为假晶fcc结构，并与CrAlN层一起外延生长，导致力学性能异常提高。当ZrO 2层厚度为1.0nm时，薄膜的硬度和弹性模量分别达到最大值47.2GPa和538.9GPa。随着ZrO 2层厚度的进一步增加，ZrO 2层不能保持面心立方结构，破坏了外延生长结构，导致力学性能下降。高温退火实验表明，在900°C以下保温30 min，硬度和弹性模量略有下降，而在1000°C退火后硬度和弹性模量明显下降。然而，即使在1000°C退火30 min后，纳米多层膜仍保持高达36.8GPa和465.7GPa的硬度和弹性模量，显示出优异的高温力学性能。
New types of CrAlN/ZrO2nanomultilayers with different ZrO2layer thickness were synthesized by reactive magnetron sputtering. The structure, mechanical properties and thermal stability were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM) and nano-indentation techniques. The results indicated that, when ZrO2layer thickness was less than 1.0nm, tetragonal-structured ZrO2layers were forced to transform to pseudomorphic fcc structure under the template effect of CrAlN layers and grew epitaxially with CrAlN layers, resulting in abnormal enhancement of mechanical properties. The maximum hardness and elastic modulus could respectively reach 47.2GPa and 538.9GPa when ZrO2layer thickness was 1.0nm. With further increase of ZrO2layer thickness, ZrO2layers could not keep fcc structure and broke epitaxial growth structure, leading to the decrease of mechanical properties. High-temperature annealing revealed that hardness and elastic modulus decreased slightly when heated at a temperature below 900°C for 30min, while dropped significantly as annealing temperature raised to 1000°C. However, even after annealing at 1000°C for 30min, the nanomultilayers still retained hardness and elastic modulus as high as 36.8GPa and 465.7GPa, showing the excellent mechanical properties at elevated temperatures.