残余应力与基底效应对光栅厚铝膜纳米压痕耦合影响研究

Coupling effect research of residual stress and substrate effect for nanoindentation process of thick aluminum film with ruling gratings

机刻中阶梯衍射光栅厚铝膜通过真空蒸镀方法获得,其内部存在残余应力,与基底效应耦合作用,增加纳米压入测试与刻划成槽模拟仿真的研究难度。为此,基于材料变形弹塑性接触理论和量纲分析方法,建立具有内部残余应力的光栅厚铝膜模型,研究内部残余应力与基底效应耦合作用对纳米压痕硬度与隆起高度的影响规律。结果显示,随着薄膜内部残余应力变大,铝膜载荷和表面隆起高度减小;受基底效应耦合影响,其二者变化趋势逐渐增大。此研究为机刻衍射光栅厚铝膜力学性能纳米压入测试及刻划成槽研究提供重要参考。

The thick aluminum film of echelle grating is obtained by vacuum evaporation,and the residual stress exists in the film. It is coupled with the substrate effect to influence the nanoindentation test results,which seriously affects the groove quality of the grating. The elastic-plastic contact theory and dimensional analysis method based on material deformation is adopted in this paper,establish a thick aluminum film grating model with residual stress,the effects of internal residual stresses and substrate effects on the hardness and height of nanoindentation are investigated. The results showed that aluminum film loading and surface uplift height decreases with the film residual stress becomes larger. Affected by the basement effect,the trend of the both changes gradually increased. The research will provide important reference for the study of mechanical properties of diffraction grating aluminum film and the process of groove ruling.