为研究光栅铝膜在机械刻划深度范围内的弹塑性变形特征,通过纳米压痕仪的Berkovich压头对现有79 g/mm中阶梯光栅铝膜进行大压深连续纳米压痕试验测试。按10 s-10 s的加-卸载方式进行压深步0.5μm、最大压深5.0μm、每个压痕步重复6次的连续压痕试验,获得整个压深尺度范围内弹性模量、硬度、最大回弹量、等效回弹锥角和回弹系数随压深的变化规律。光栅镀铝膜层材料的弹性模量、硬度在浅表层体现出较强尺寸效应,同时在镀铬过渡层和玻璃基底综合效应的影响下出现"拐点"极值;残余压痕的最大回弹量随压深近似线性增加,但是相对压深的回弹量、等效回弹锥角和回弹系数均随压深减小,这表明光栅铝膜在机械刻划深度范围内的回弹性能受压入深度的影响较大。这对于认识现有中阶梯光栅镀铝膜层材料的力学性能并改进镀膜工艺具有重要意义。
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.