Effect of pre-corroded on fatigue behavior of MAO treated ZK60 magnesium
alloy in a simulated body fluid
Abstract
A bio-ceramic coating was prepared on the surface of ZK60 magnesium
alloys by micro-arc oxidation (MAO) method. The substrate (BM) and
coated (MAO) specimens were pre-corroded in a simulated body fluid (SBF)
for 12 h. Strain-controlled and stress-controlled loading modes were
used to conduct fatigue tests for the two specimens, respectively. The
cyclic deformation behavior of the two specimens with non-corroded and
pre-corroded was studied. The mechanism of cyclic deformation under
different loading conditions is related to twinning and slip. At the
same test conditions, the fatigue life of the non-corroded BM specimen
is higher than that of the non-corroded MAO specimen, while the fatigue
life of the pre-corroded MAO specimen is higher than that of the
pre-corroded BM specimen. A modified total strain energy model is
proposed and the precision of life prediction is higher than that of
traditional fatigue model.