摘要：近年来人们对外观逼真、生物相容性好、力学性能好的牙科材料的需求越来越大。本实验采用水基电泳沉积的方法沉积氧化锆陶瓷层，利用纳米压痕测试研究氧化锆陶瓷层的硬度与弹性模量。

利用纳米压痕仪测试不同电压下沉积的氧化锆陶瓷层后，50V的直流电源沉积出的陶瓷层硬度为21.09GPa，弹性模量为195.75GPa。随后对50V电压下沉积出的氧化锆1250-1450℃的烧结温度烧结，利用X射线衍射仪、扫描电镜等表征陶瓷层的微观结构，分析微观结构对力学性能的影响。XRD实验结果表明烧结后生成以单斜相为主相的氧化锆晶体，通过SEM观察可知随着温度升高，氧化锆晶粒越来越大。综合XRD、SEM、纳米压痕测试与密度测试结果可知，1250℃与1300℃烧结的氧化锆陶瓷晶粒过小，力学性能较差。1400℃与1450℃烧结温度造成过烧现象，薄膜力学性能下降。而1350℃烧结温度烧结的氧化锆陶瓷层硬度与弹性模量均高过其他烧结温度，分别为22.93GPa，弹性模量为264.28GPa，密度为5.60g/cm3。最后利用基于多步加载卸载方法的纳米测试法研究氧化锆陶瓷层的尺寸效应。实验发现硬度在载荷小于11.6mN和深度小于164.6nm的范围内呈现反向压痕尺寸效应，当深度大于568nm时，硬度的改变与压痕深度无关，一直保持22GPa的稳定值。氧化锆试样的弹性模量随着深度的增加迅速下降。当深度大于568nm，弹性模量逐渐降低。

关键词：氧化锆陶瓷；电泳沉积；纳米压痕测试。

Abstract：In recent years, people on the appearance of realistic, good biocompatibility, good mechanical properties of dental materials growing demand. In this study, the zirconia ceramic layer was deposited by water-based electrophoretic deposition, and the hardness and elastic modulus of zirconia ceramic layer were studied by nanoindentation test.

The hardness of the ceramic layer deposited by the 50V DC power source was 21.09GPa and the elastic modulus was 195.75GPa after the nano-indentation was used to test  the  zirconia  ceramic  layer  deposited  at  different  voltage.  Then,  the      sintering

temperature   of   zirconia   1250-1450    ℃   deposited   at   50V   was   sintered.    The

microstructure of the ceramic layer was characterized by X-ray diffraction and scanning electron microscopy. The effect of microstructure on the mechanical properties was analyzed. The results of XRD show that the zirconia crystals with single oblique phase are formed after sintering, and the grain size of zirconia is increasing with the increase of temperature. The XRD, SEM, nanoindentation and density test results show that the ceramic grains sintered at 1250 ℃ and 1300 ℃ are too small and the mechanical properties are poor. 1400 ℃ and 1450 ℃ sintering temperature caused by burning phenomenon, the mechanical properties of the film decreased. The hardness and elastic modulus of the zirconia ceramic layer sintered at 1350 ℃ were higher than that of other sintering temperatures of 22.93GPa,the elastic modulus was 264.28GPa and the density was 5.60g / cm3. Finally, the size effect of zirconia ceramic layer was studied by nanoindentationtest method based on multi-step loading and unloading method.  It is found that the hardness exhibits a reverse indentation effect in the range of less than 11.6mN and less than 164.6nm. When the depth is more than 568nm,the change of hardness is independent of the indentation depth and keeps the stability of 22GPa. The elastic modulus of the zirconia sample decreases rapidly with increasing depth. When the depth is greater than 568nm, the elastic modulus gradually decreases.

Key words: zirconia ceramics; electrophoretic deposition;nanoindentation test.

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