Residual stresses due to quenching in aluminum forging parts for aerospace applications: finite element analysis and contour method measurement

Shape correction plays a significant role in the optimization of manufacturing cycle and cost of machined aluminum aircraft parts. Partial or complete removal of machining distortions is therefore of great interest to aircraft manufacturers. Residual stress that develops during the quenching process is a main source of such distortions.

In the present study, Finite Element Analysis was used in order to predict temperature and strain/stress fields that develop during heat treatment of 7075-T73 aluminum forged test blocks, from Boeing 777 hinge and latch beams components. The heat transfer problem is addressed first and then the resulting transient temperature field provides an input to the mechanical problem. Residual stress predictions are then compared with Contour Method measurements. Finally, the deformation that results from non-symmetrical material removal is simulated, where the previously calculated residual stress fields are used as an input