调制周期对磁控溅射WB2/CrN多层薄膜力学性能的影响

目的研究调制周期对磁控溅射WB_2/CrN多层膜结构及性能的影响。方法通过双靶直流磁控溅射法,在硅片、石英玻璃片及不锈钢上,制备Al B_2型WB_2薄膜与CrN薄膜及其多层复合薄膜,采用X射线衍射及扫描电子显微镜对其相结构及形貌进行观察和分析,使用维氏显微硬度仪及划痕仪对多层膜的硬度及膜基结合力进行研究。结果磁控溅射WB_2/CrN多层薄膜呈现出柱状生长趋势,且层状结构明显,仅当调制周期大于317 nm时,多层膜中才出现WB_2晶体的衍射峰。结论多层膜中的WB_2薄膜在本实验条件下的临界结晶厚度大于150 nm。随着调制周期的减小,CrN层生长取向发生由(200)晶面向多晶面的转变,WB_2层生长取向由(101)晶面向(001)晶面转变。多层膜硬度随调制周期的减小大体呈下降趋势,在调制周期为317 nm时达到最大值。结合力变化趋势与硬度相反,CrN层及多层界面有助于复合薄膜膜基结合强度的提高。

Effects of Modulation Period on Mechanical Properties of Magnetron Sputtered WB2/CrN Multilayer Films

The work aims to study effects of modulation period on structure and properties of magnetron sputtered WB2/CrN multilayer films. AlB2 type WB2 and CrN films as well as corresponding multilayer composite films were deposited on silicon ship, quartz glass sheet and stainless steel, respectively in the method of dual targets DC magnetron sputtering. Phase structure and morphology were observed and analyzed with X ray diffractometer and scanning electron microscope, and hardness and film adhesion of the multilayer films were studied with Vickers microhardness tester and scratch tester. Magnetron sputtered WB2/CrN multilayer films tended to grow in columnar mode and had obvious stratified structure. Diffraction peaks of WB2 crystal were present only in the multilayer films when modulation period was over 317 nm. Critical crystallization thickness of WB2 film in the multilayer films was over 150 nm in this experiment. Growth orientation of CrN monolayer changed from (200) crystal plane to multiple crystal planes, and WB2 layer from (101) to (001) as the modulation period decreased. Hardness of the multilayer films decreased as the modulation period decreased in general, and reached the maximum when the modulation period was 317 nm. Adhesion showed a reversed variation trend against hardness. CrN layer and multilayer interfaces contributed to film adhesion improvement of composite films.