FEM simulation and experimental study on the quenching residual stress of aluminum alloy 2024

Abstract

Finite element models were established to simulate the quenching processes of aluminum alloy 2024 blocks under different quenching conditions. The surface cooling curves of aluminum blocks in different quench media were obtained by experiment. Inverse heat-transfer calculations were applied to determine the heat-transfer coefficient curves. Finite element model was used to predict residual stresses developed after quenching process by quenching aluminum blocks with different thicknesses (20 mm ≤ d ≤70 mm) into two kinds of quenchants (water and polyalkylene glycol solution). The influence of block thickness and quenchant on residual stresses was investigated by both finite element method simulation and experiments. To validate the simulation results, the X-ray diffraction method was used to measure the residual stresses developed in aluminum alloy 2024 blocks after quenching process. The agreement between model and experiment was good. It was concluded that both block thickness and quench media had critical influences on residual stresses. When the thickness of the aluminum block increased from 20 to 50 mm, the residual stress value at the center of the block increased by 100% and the increase of the residual stress became insignificant after 50 mm. In d = 20 and 30 mm cases, polyalkylene glycol quench conditions were proved to cause lower levels of residual stress than water quench conditions.