Nano-indentation Test for Aluminum Film of Echelle Grating

The nano-indentation test with 3 μm in depth was carred out in the aluminum film of echelle grating with linear density of 79 grooves·mm-1. The initially optimized parameter combination was obtained by finite element simulation combining with orthogonal analysis and the best parameters were given by iterative optimization. Results show that the mean value of Young's modulus of echelle grating aluminum film was 85.7 GPa. The optimum tested parameter combination of echelle grating aluminum film was 134 MPa in yield stress and 0.09 in strain hardening exponent. The accuracy of the finite element simulation model of grating indentation was relatively sensitive to the yield stress.