关键词: 尺寸效应, 回弹, 基底效应, 铝膜, 纳米压痕, 中阶梯光栅

Abstract: For the research on elasto-plastic deformation characteristics of grating aluminum in the mechanical ruling depth range, a series of large depth nanoindentation tests are completed about the existing 79 g/mm echelle grating with a Berkovich indenter on a nanoindentation instrument. Some changing regularities of the grating aluminum film parameters including the Young’s modulus，hardness, biggest recovery, equivalent recovery conical angle and coefficient of restitution are got with the indentation depth increasing, by 10 s-10 s load and unload continual indentation method with a depth step 0.5 μm, largest depth 5.0 μm, and 6 repeats at the same depth. The Young’s modulus and hardness values have large size effects in the shallow surface layer of the aluminum film, and have their extreme values at the corresponding changing points under synthetic effects of the intermediate Cr film and the glass substrate. The largest recovery values of the final indentations have a linear relation increasing with the depth, but the relative recovery depth, the equivalent recovery conical angle and the coefficient of restitution all decrease with the depth. All these findings indicate that the indentation depth has an important affection on the recovery characteristics of grating aluminum film in the depth of mechanical ruling, which are very meaningful for recognizing the mechanical characteristics of echelle grating film and improving the evaporation process.

Key words: Aluminum film, Echelle grating, Nanoindentation, Recovery, Size effect, Substrate effect