14th International Conference on Shot Peening

Application of shot peening to enhance precipitation hardening effect in aluminium alloys

Michal Jambor, Libor Trško, Ivo Šulák, Sara Bagherifard, Mario Guagliano, Otakar Bokůvka

Institute of Physics of Materials, Czech Academy of Sciences, www.ipm.cz , Zizkova 22, Brno, Czech Republic – jambor@ipm.cz , sulak@ipm.cz

Research Centre of the University of Zilina, www.researchcentre.sk, Zilina, Slovak Republic – libor.trsko@uniza.sk, otakar.bokuvka@fstroj.uniza.sk

Politecnico di Milano, Department of Mechanical Engineering, www.mecc.polimi.it,Via la Masa 1, Milano, Italy – mario.guagliano@polimi.it , sara.bagherifard@polimi.it

Introduction

High strength aluminium alloys obtain optimal mechanical properties after T8 heat treatment, which consist of solution annealing and stretching, followed by artificial aging. The stretching prior to artificial aging is important to increase the dislocation density, what multiplies the number of precipitate nucleation sites. This process is possible to perform only on standardized semi-products, but not on, for example, welded structures, due to their complex shape. Application of shot peening prior to artificial aging can partially substitute the stretching process and increase the dislocation density in sub-surface layers, what can improve the strengthening effect of the artificial aging.

Objectives

The effect of shot peening performed prior to precipitation hardening on high strength Al-Cu-Li aluminium alloy was investigated with aim to increase mechanical properties, mainly fatigue strength.