调制比对TC4/ZrB_2多层膜结构和机械性能的影响

Effect of modulation ratios on microstructure and mechanical properties of TC4/ZrB_2 amorphous multilayers

为研究不同调制比对TC4/ZrB_2(tTC4∶tZrB_2)纳米多层膜结构和机械性能的影响,采用磁控溅射镀膜技术在Si基底上设计制备了一系列具有不同调制比(tTC4∶tZrB_2)的TC4/ZrB_2纳米多层薄膜,利用X线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(HRTEM)和纳米压痕系统对多层膜的晶体结构、断面形貌、硬度、弹性模量和膜基结合情况进行测量,并通过退火处理对多层膜的热稳定性进行分析.结果表明:界面的扩散和畸变抑制了两调制层的结晶生长,使多层膜呈非晶结构.在tTC4∶tZrB_2为1∶5时,多层膜的硬度和弹性模量均达到最大,分别为22.40 GPa和263.11 GPa.在550℃退火后,多层膜硬度增加约2.6GPa.分析认为,两材料的模量差和界面处形成的交变应力场强化了材料的硬度,而混合界面的存在增强了多层膜的高温稳定性能.

In order to study the effect of different modulation ratios on the structure and mechanical properties of TC4/ZrB2 （tTC4：tZrB2） nanomuhilayers, a series of TC4/ZrB2 nanomuhilayers with different modulation ratios （tTC4：tZrB2） were designed and fabricated on the Si substrate by magnetron sputtering system. X-ray diffraction （XRD）, scanning electron microscope （SEM）, high resolution transmission electron microscopy （HRTEM） and nanoindentation system were used to measure crystal orientation and structure, cross-sectional morphology, hardness, elastic modulus and film-substrate cohesion, and thermal stability of the multilayers was analyzed after annealing. The results show that the diffusion and distortion of the in- terface suppress the crystal growth of the two modulation layers and make the film exhibit amorphous structure. The hardness and elastic modulus of multilayer films are the highest at txc4 ： tZr~ of 1 ： 5, respectively 22.40 GPa and 263.11 GPa. After annealing at 550 ~C, the muhilayer fihn hardness increased by about 2.6 GPa. It is concluded that the modulus difference between the two materials and the alternating stress field formed at the interface enhances the hardness of the material, and the presence of the mixed interface enhances the high stability of the multilayer fihn.