Analysis of Residual Deformations and Stresses in a Rolled Sheet of AA 6082-T6 Aluminium Alloy Using a Micro-indent Method

摘要

The residual deformation and stress states, corresponding to a rolled product of AA 6082-T6 aluminium alloy used in naval structures, were comprehensively analyzed from data obtained using an optimized micro-indent method. A great advantage of using this method, which needs a measuring machine, is to avoid specific equipments and qualified personnel. Furthermore, the absolute measurement error of this technique is very small (±0.9 MPa). The results obtained through the analysis of Mohr's circles reveal compressive normal components prevailing in the residual deformation and stress states. A very important aspect is that the direction of the more compressive component is very close to the rolling direction. This may indicate the importance of the rolling process, which is previous to the thermal hardening process T6, in the final states of residual deformation and stress. Finally, the residual stress state of the evaluated material, which is quasi-isotropic, was compared with the failure stress by using the von Mises yield criterion for ductile materials.