Open AccessThe influence of Shot Penning on fatigue crack growth rate of Chemical Milling product Al-2524-T3 alloys which has been Stretched
Author(s) -
Yovial,
Jamasri,
Yos Nofendri,
Wenny Marthiana,
Duskiardi
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/990/1/012025
Subject(s) - materials science , intensity (physics) , growth rate , shot (pellet) , fracture mechanics , metallurgy , stress intensity factor , crack closure , composite material , yield (engineering) , paris' law , optics , mathematics , physics , geometry
This study aims to investigate the influence of shot penning on fatigue crack growth rate of chemical milling product Al 2524-T3 which have been stretched. This alloys were stretched beyond yield stress, namely 1%, 3% and 5% of each, and then performed chemical milling process of one side. The etching used in chemical milling process were NaOH+Na 2 S+H 2 O solutions with certain concentration. The surface was performed shot penning process with varying intensity of 0.03 A, 0.05 A and 0.07 A, respectively. These material were then tested its crack growth rate. The crack growth rate tests were performed under 20% stress level, stress ratio of 0.3 and at frequency 7-13 Hz. The average of crack propagation data against the cycle number were processed using an incremental method, in accordance with ASTM E647 standard, to obtain crack growth rate curve (da/dN vs. ΔK). The results show that the increase of shot penning intensity has no significant effect on the fatigue life, with the growth average of 4,5%. The highest increase occurred at the shot intensity of 0.03 A, 0.2 times its chemical milling, while the lowest decrease occurred at the shot intensity of 0.07A, 0.012 times its chemical milling. The crack retardation effect at the beginning of the crack plays a role in reducing the crack propagation rate.