Study of through-thickness residual stress by numerical and experimental techniques

Abstract

The quenching process of aluminium alloys is modelled using the finite element method. The study of residual stress field induced by quenching is divided into two: the thermal and mechanical aspects. In the thermal problem, the general heat conduction equation is solved and the temperature field during quenching is calculated. In the mechanical problem, the calculated temperature field and mechanical properties are used to predict the residual stress field. In this paper, the two different boundary conditions used in the thermal problem are examined. The first is surface convection using the appropriate heat transfer coefficient. The second is the temperature variation measured at the surface of the part. These boundary conditions are compared, and the advantages and the drawbacks of each are shown. The influence of different quenching parameters on the level of residual stress is studied. To validate the quenching modelling, the incremental hole drilling and neutron diffraction methods are used to measure the residual stress field in the studied parts. The hole drilling technique has been adapted to measure the residual stress through a larger thickness of the part. The aim of this paper is the combination of numerical and experimental techniques for the investigation of the through-thickness residual stress field.