Effect of surface integrity on fatigue life of 7075‑T6 aluminum alloy by combination of fine turning with hydrostatic deep rolling

In this study, the 7075-T6 aluminum alloy sample was firstly prepared by fine turning(FT) process, and then the surface treatments were subjected to hydrostatic deep rolling(HDR), including constant pressure deep rolling(CPDR) and increasing pressure deep rolling(IPDR). Subsequently, the influence of surface integrity on the fatigue life of the 7075-T6 aluminum alloy is investigated by the combination of FT with HDR. The results show that the fatigue life of IPDR and CPDR samples is increased significantly by 148% and 450% compared to the FT sample in the tensile-compression fatigue test. The improved fatigue life of IPDR and CPDR samples is a result of reduced significantly surface roughness and the increase of surface compressive residual stress, surface micro-hardness and the depth of plastic deformation layer. In addition, the deeper plastic deformation layer is the main reason for the higher fatigue life of the CPDR sample than the IPDR sample.

Opracowanie rekordu ze środków MEiN, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2022-2023)