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Effects of humidity and temperature on the fatigue behaviour of an extruded AZ61 magnesium alloy
Author(s) -
SAJURI Z. B.,
MIYASHITA Y.,
MUTOH Y.
Publication year - 2005
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/j.1460-2695.2005.00775.x
Subject(s) - materials science , relative humidity , humidity , fatigue limit , composite material , corrosion fatigue , metallurgy , magnesium alloy , alloy , stress (linguistics) , corrosion , physics , thermodynamics , linguistics , philosophy
Load‐controlled fatigue tests were performed at 20 and 50 °C using two relative humidity levels of 55 and 80% to characterize the influence of humidity and temperature on the fatigue behaviour of an extruded AZ61 magnesium alloy. Fatigue tests were also conducted at 150 °C. No significant variation in fatigue properties was noticed with respect to temperature over the range from 20 to 50 °C for both the humidity levels. Fatigue limits in the range 140–150 MPa were observed for relative humidity of 55%. Fatigue strength decreased significantly with increase in temperature to 150 °C. Further, a significant reduction in fatigue strength with a fatigue limit of ∼110 MPa was observed with increase in relative humidity to 80% at 20 and 50 °C. The crack initiation and propagation remained transgranular under all test conditions. The fatigue fracture at low stress amplitudes and high relative humidity of 80% results from the formation of corrosion pits at the surface and their growth to a critical size for fatigue‐crack initiation and propagation. The observed reduction in fatigue strength at high humidity is ascribed to the effects associated with fatigue–environment interaction.