Impact of the drilling process on the surface integrity and residual fatigue strength of 2024-T351 aluminum parts
Résumé
This paper investigates the influence of the drilling process on an aluminum 2024-T351 part in terms of surface integrity and fatigue strength. Two drilling processes (axial; orbital) are considered. The surface integrity is studied through surface roughness measurements, microstructure and hardening analysis and residual stress assessment. An innovative Hole Opening Comparative Technique is set up to assess the residual stress state. Fatigue tests are conducted with open-hole specimens, and on filled-hole samples (double-lap bearing strength tests). The strain hardening of the hole subsurface seems to be the main factor influencing the fatigue behavior, associated with a residual stress state.