Measurement of residual stress in micro-end-milling of AMS 5833 Co-Cr-Ni alloy thin film

It's difficult to measure the residual stress in the metal thin films. In the present work, the microbridge testing method was used to calculate the residual stress in the AMS 5833 Co-Cr-Ni alloy film (thickness in the range of 8 μm to 14 μm). The samples were machined by a 3 axes precision micro-milling machine tool (300 mm × 300 mm × 290 mm) with the two fluted carbide end mills (cutting diameter: 0.15 mm). Using the MTS Nano indenter® XP system, we conducted experiments to determine the Young's modulus of the machined film from the load-displacement data. And then, the theoretical analysis of microbridge test based on the Young's modulus measured by the nonoindentation was performed to evaluate the residual stress in the Co-Cr-Ni alloy film. The results show that the Young's modulus is 55.17 ± 3.96 GPa, the calculated residual stress is 188.9 ± 2.36 MPa.