Improvement in fatigue life of Al 7475-T7351 alloy specimens by applying ultrasonic and microshot peening
2016; Elsevier BV; Volume: 92; Linguagem: Inglês
10.1016/j.ijfatigue.2016.06.022
ISSN1879-3452
AutoresRafael Ramos, Natália Ferreira, J.A.M. Ferreira, C. Capela, António Castanhola Batista,
Tópico(s)Advanced machining processes and optimization
ResumoShot peening and ultrasonic peening are widely used mechanical surface treatment in the automotive and aerospace industries to improve the fatigue life of metallic components. This work aims to further improve the mechanical properties of the AA7475-T7351 alloy by applying three different peening processes: Ultrasonic Peening (USP) and Microshot Peening with two different beads size (MSP). A systematic study was carried out on the roughness, surface hardening, residual stress profiles and fatigue life. Uniaxial fatigue tests were conducted. Residual stresses were evaluated by X-ray diffraction, and the fracture surface was observed and analysed with a Scanning Electron Microscope. The microstructures of the specimens were observed by optic microscope. Microhardness and roughness were also measured. All of the surface treatments enhanced the specimens fatigue lives, despite having created different superficial conditions. In addition, the experimental results and analytic predictions based on the Molski-Glinka approach were compared, and in general, agree well.
Referência(s)