Behavior of the Rate of Fatigue Crack Propagation after Shot Peening in Aluminum Alloy 2024 T3

Author:  D.H.S. Costa, M.A.S. Torres and C.A.R.P. Baptista
Source:  Conf Proc 2014: ICSP-12 Goslar, Germany (pgs.124-129)
Doc ID:  2014062
Year of Publication:  2014
Abstract:  
Shot peening is a process that may induce improvements in the fatigue behavior of the material by inducing compressive residual stresses in their surfaces. This work studies the influence of the shot peening process on the rate of fatigue crack propagation in 2024-T3 aluminum alloy. Compact tension specimens were initially cracked in fatigue and then subjected to shot peening process on both sides. After application of shot peening process, the fatigue test was restarted. Tests with constant amplitude, the load ratios (R) of 0.1 and 0.5, in two thicknesses were conducted to examine the possible effects of stress state on the variation of the rate of crack propagation. The effects of two values of shot peening intensity are studied for both load ratios. Comparative curves of the behavior of the rate of fatigue crack propagation, with and without shot peening process, are presented and discussed their differences. The existence of the effect of shot peening process on the behavior of the rate of fatigue crack propagation is displayed when the compressive residual stresses induced by the process influence the value of the effective stress intensity factor range (ΔKeff).