Experimental characterization and finite-element analysis of an AlSi1060 aluminium film/glass substrate system under in situ laser-assisted indentation

Authors:
Publisher website
Google Scholar
Abstract
To clarify the effect of in situ laser heat input on the apparent indentation response of an AlSi1060 aluminium film/glass substrate system, an integrated in situ laser heating–instrumented indentation platform and a calibrated coupled thermo-mechanical finite element model were developed. Displacement-controlled indentation tests were conducted at depths of 0.5–5 μ m under laser powers of 0, 5, 10 and 15 W. Thermal-drift control measurements were performed under the same conditions, and the raw displacement signals were corrected before extracting load, hardness, energy and unloading-recovery parameters. With increasing laser power, the P – h curves shift downward and the peak load required to reach the same prescribed depth decreases continuously. At h max = 5 μ m, P max and hardness H decrease by approximately 44% and 45%, respectively. The experimentally defined softening coefficient λ shows no statistically significant depth dependence within the investigated range but decreases markedly with laser power, indicating that the load-level reduction is mainly governed by local heat-input intensity. Apparent Nix–Gao-type fitting shows that both H 0 ,app and h *,app decrease with laser power; these parameters are interpreted as system-level descriptors rather than intrinsic properties of the aluminium film alone. Finite element results show that the high-stress region remains beneath the indenter, while the stress level needed to sustain the same indentation depth decreases with heat input. Energy decomposition confirms that plastic dissipation dominates under all conditions, with η pl increasing slightly from 0.933 to 0.958 and R e decreasing from 0.067 to 0.042. After unloading, indentation-derived residual depth increases, optical micrographs show clearer projected residual boundaries, and simulation-derived profiles indicate enhanced local pile-up. These results demonstrate that in situ laser heating reduces the apparent load-bearing resistance of the film/substrate system, suppresses unloading recovery and improves residual-shape retention.
Funding Information
  • National Natural Science Foundation of China (52375405)
  • Natural Science Foundation of Jilin Province (20240101078JC)
  • Scientific Research Project of Jilin Provincial Department of Education (JJKH20230809KJ)
  • Lu Quan Innovation Fund

This publication has 31 references indexed in Scilit: