纳米TiO₂涂膜玻璃的力学性能研究

【作者】 冀国俊；

【导师】 史志铭；

【作者基本信息】 内蒙古工业大学 ， 固体力学， 2005， 硕士

【摘要】 TiO₂ 纳米薄膜是一种重要的无机功能材料,因其具有良好的光学、电学、化学保护等性能,所以越来越受到人们的关注,近年来在许多领域得到了广泛应用。本文采用溶胶—凝胶法在玻璃表面制备了均匀的TiO₂ 纳米薄膜。通过X射线衍射、原子力显微镜和纳米压痕等实验方法,研究了掺铈和未掺铈的TiO₂ 薄膜的表面形貌、晶体结构和力学特性,并用有限元软件对表面压痕实验进行了模拟;同时对未涂薄膜以及涂覆不同层数薄膜的玻璃试样的力学性能进行了测试,探讨了纳米薄膜对玻璃基体表面增强增韧的作用机理。研究结果表明随着热处理温度的升高,薄膜中锐钛矿型TiO₂ 逐渐增加,当温度升高到600℃时,纯TiO₂ 薄膜中部分锐钛矿相转变为金红石相,而铈离子掺杂的TiO₂ 薄膜中并未发生锐钛矿相向金红石相的转变;TiO₂ 薄膜的AFM 结果显示,TiO₂ 薄膜颗粒大小在纳米尺度,并且薄膜表面平整,粗糙度小,Ce⁴⁺掺杂后薄膜的结构更加致密,粒径变小;纳米压痕实验表明,涂膜玻璃表面的硬度和弹性模量随着TiO₂ 薄膜涂覆层数的增加基本不变,Ce⁴⁺掺杂后变化也不明显;玻璃基体的力学性能如弹性模量、抗拉强度、弯曲强度和断裂韧性随着TiO₂ 薄膜涂覆层数的增加而提高,特别是Ce⁴⁺掺杂后这种增强作用更为显著。更多还原

【Abstract】 TiO₂ nanofilm is a very important function inorganic material. It hasperfect optical properties, good electrical properties and high chemicalresistibility. So more and more research works have been put in this aspect andthe film is widely used in many fields in recent years.The smooth nanometer TiO₂ thin films coated on glass substrates wereprepared by the sol-gel processing in this work. The morphology, crystalstructure and mechanical properties of Ce⁴⁺ -doped/undoped TiO₂ thin films werecharacterized by means of XRD, AFM and nano-indentation. Moreover, theindentation experiments were simulated using a finite element method （FEM）.The mechanical properties of glass substrates with different coating layers weretested. Then, the effect of TiO₂ thin film on surface modification of the glasssubstrate was discussed.The XRD results indicated that the anatase content in the films wasincreased with the increasing of heat treatment temperature. When treated at600℃,the anatase phase was partially converted into rutile in pure TiO₂ thinfilms; however, it was not happened in Ce⁴⁺-doped TiO₂ thin films. The AFMresults showed that the diameter of TiO₂ particles in the film were in the rangeof nanometers, the surface of films was smooth and the roughness was small.When doped with Ce⁴⁺, the crystal structure of anatase was much denser and thegranularity was much smaller. The nano-indentation results showed that theYoung’s modulus and hardness of the TiO₂-coated substrates were enhancedwith the increasing of the coating times, but the changes were not evident. Themechanical properties of glass substrates such as Young’s modulus, tensilestrength, bending strength and fracture toughness were sufficiently enhancedwith the increase of coating layers.更多还原