纳米多孔铜膜的制备和力学性能研究

发布时间：2018-02-25 15:21

本文关键词： 纳米压痕脱合金腐蚀弹性模量硬度　出处：《西安理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：近三十年来,随着纳米科技的日趋展开,纳米材料因为其一系列优良的性能而使其应用遍及各个领域,也获得了越来越多研究人员的关注,各国研究人员都在继续为了发掘纳米材料更加优良的性能而努力,这些优良的性能都离不开表面效应的影响。然而至今为止,纳米材料相关的研究仍然有很大的空间值得我们去探索。本文针对纳米多孔铜薄膜的制备方法和力学性能做出研究,主要内容分为以下三个方面。首先,分析讨论了如何制备纳米多孔铜膜的问题。一般镀膜方式主要采用电化学沉积法、蒸发镀膜、磁控溅射法中的单独溅射法等,且主要研究金银合金。本文采用磁控溅射法中的共溅射法制备出1μm厚的比例为2:8的Cu-Zn前驱体合金,进一步采用酸溶液进行脱合金腐蚀,去除掉活性较高的Zn,从而得到纳米多孔铜膜。磁控溅射镀膜可通过调整电流,电压,时间等参数获得特定比例的合金薄膜,腐蚀过程必须无菌操作。研究发现Cu-Zn合金镀膜以硅片为基底更容易得到理想的薄膜,合金脱合金腐蚀过程中,硫酸的浓度较低时,且采用滴定腐蚀的方式,更容易得到表征良好的薄膜。其次,用纳米压痕仪采用压入法进行实验,压入薄膜深度为1000nm,测量纳米多孔铜膜力学性能并进行研究。一般关于纳米材料的研究主要是关于其导电性,导热性、催化性等性能的研究,本文主要研究力学性能。实验测得纳米多孔铜膜的弹性模量和硬度相对于宏观块体铜弹性模量和硬度分别提升了一倍和九倍。所以,纳米多孔铜膜相对于宏观块体铜力学性能有了很大的提升。而且针对宏观块体铜,微观状态纳米铜膜,湿润状态纳米多孔铜膜,干燥状态纳米多孔铜膜,分别画出荷载-位移曲线,通过对比直观发现,弹性模量和硬度呈现梯度增加,而且多孔结构薄膜相对与无孔结构薄膜弹性的性能也有了很大提升,由此可见,薄膜孔洞结构有助于提高弹性。最后,运用量纲分析法得到适用于薄膜/硅片的幂硬化本构模型,结合ANSYS仿真模拟纳米压痕压入过程,将实验所得参数代入ANSYS中,并设定10个荷载步来模拟压入过程,提取每一步的荷载值代入本构模型,最终求解得到纳米多孔铜膜的屈服强度和幂硬化指数,从而进一步得到薄膜的应力应变关系,并且将理论所得的应力应变关系代回到ANSYS中,得到变形图,通过与实验数据对比发现,仿真所得最大变形值为与实验所得最大压入深度值非常接近,所以可认为数据具有很好的可靠性。最终画出纳米多孔铜膜和宏观块体铜的应力应变曲线进行对比,直观看出薄膜相对宏观材料力学性能的优越性。
[Abstract]:In the past 30 years, with the development of nanotechnology, nanomaterials have been widely used in various fields because of their excellent properties, and have been paid more and more attention by researchers. Researchers from all over the world are continuing their efforts to discover better properties of nanomaterials that can not be separated from the effects of surface effects. There is still a lot of space for us to explore the related research of nano-materials. The preparation method and mechanical properties of nano-porous copper thin films are studied in this paper. The main contents are as follows: first of all, The problems of preparing nano-porous copper films are analyzed and discussed in this paper. The common methods of coating are electrochemical deposition, evaporation deposition, single sputtering in magnetron sputtering, and so on. In this paper, a 1 渭 m thick Cu-Zn precursor alloy with a ratio of 2 渭 m to 8 was prepared by co-sputtering in the magnetron sputtering method, and the alloy was further corroded by acid solution. By removing the highly active Zn2 +, a nano-porous copper film can be obtained. The magnetron sputtering film can be obtained by adjusting the parameters such as current, voltage, time and other parameters to obtain a specific proportion of the alloy film. It is found that Cu-Zn alloy coating on silicon substrate is easier to obtain ideal thin films. When the concentration of sulfuric acid is lower in the process of alloy dealloying, the titration corrosion method is used. It is easier to obtain well characterized films. Secondly, the nanoindentation method is used to carry out the experiments. The depth of the film is 1000 nm, the mechanical properties of nano-porous copper film are measured and studied. Generally, the research on nanomaterials is mainly about their electrical conductivity, thermal conductivity, catalytic properties, etc. In this paper, the mechanical properties of nano-porous copper film are studied. The elastic modulus and hardness of nano-porous copper film are increased by two times and nine times respectively compared with that of macroscopic bulk copper film. The mechanical properties of nano-porous copper films have been greatly improved compared with those of macroscopic bulk copper films, and the nano-porous copper films in macroscopic bulk copper, nano-copper films in micro-state, nano-porous copper films in wetted state, and nano-porous copper films in dry state have been studied. The load-displacement curves were drawn respectively. It was found that the elastic modulus and hardness showed a gradient increase, and the elastic properties of the porous structure film were greatly improved compared with the porous structure film. The pore structure of thin film is helpful to improve the elasticity. Finally, the power hardening constitutive model suitable for thin film / silicon wafer is obtained by using dimensional analysis method, and the experimental parameters are substituted into ANSYS by ANSYS simulation to simulate the indentation process of nanoindentation. Ten load steps were set to simulate the indentation process, and the load values of each step were extracted into the constitutive model. Finally, the yield strength and power hardening exponent of the nano-porous copper film were obtained, and the stress-strain relationship of the film was obtained. In addition, the stress-strain relation obtained by theory is replaced by ANSYS, and the deformation diagram is obtained. By comparing with the experimental data, it is found that the maximum deformation obtained by simulation is very close to the maximum indentation depth obtained by experiment. Finally, the stress-strain curves of nano-porous copper film and macroscopic bulk copper are compared, and the superiority of the film compared with the mechanical properties of macroscopic material can be seen intuitively.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1

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