通过反应磁控溅射制备了一系列不同Si3N4层厚的HfC/Si3N4纳米多层膜,采用X射线光电子能谱、X射线衍射、扫描电子显微镜和微力学探针表征了多层膜的微结构、硬度与弹性模量,研究了Si3N4层厚度变化对纳米多层膜微结构与力学性能的影响。结果表明,溅射的Si3N4粒子不与C2H2气体反应,因NaCl结构HfC晶体调制层的模板效应,溅射态为非晶的Si3N4层在厚度小于约1 nm时被强制晶化,并与HfC晶体层形成共格外延生长结构,多层膜呈现强烈的(111)择优取向柱状晶,其硬度和弹性模量显著上升,最高值分别达到38.2 GPa和343 GPa。进一步增加Si3N4层的厚度后,Si3N4层转变为以非晶态生长,多层膜的共格外延生长结构受到破坏,其硬度和模量也相应降低。
The super-hard HfC/Si3N4 nano-multilayers were deposited by multi-target reactive magnetron sputtering.The impacts of the growth conditions on its mechanical properties were studied.The microstructures and properties were characterized with X-ray diffraction,X-ray photoelectron spectroscopy,scanning electron microscopy and conventional mechanical probes.The results show that the thickness of the amorphous Si3N4 layer significantly affects the microstructures,and the hardness and elastic modulus of the multi-layers.For example,at a thickness less than 1.0 nm,the epitaxial growth of the Si3N4 film occurs because of the strong influence of the cubic HfC,resulting in a rapid increase of the hardness and elastic modulus up to 38.16 GPa and 343 GPa at a thickness of 0.6 nm,respectively.We found that the amorphous Si3N4 layer,usually with a thickness1 nm,deteriorates the mechanical properties of the multilayer to a varying degree.