Effect of frequency on fatigue crack growth behavior of magnesium alloy AZ61 under immersed 3.5 mass% NaCl environment

作者：Rozali Shaifulazuar; Mutoh Yoshiharu^*; Nagata Kohsoku

来源：Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2011, 528(6): 2509-2516.

DOI：10.1016/j.msea.2010.12.048

• Fatigue crack growth
• Frequency
• Corrosion
• NaCl
• Crack closure
• Magnesium alloys

Fatigue crack growth test of AZ61 magnesium alloy was carried out under immersed NaCl environment at frequencies of 15, 5 and 0.5 Hz under a stress ratio of 0.1. In order to investigate the effect of frequency on fatigue crack growth behavior in detail, additional tests at frequencies ranged from 15 to 0.01 Hz were conducted under a constant Delta K of 3.25 MPa M(1/2). Effect of frequency was clearly observed in low Delta K region, where fatigue crack growth rate decreased with decreasing frequency. Crack closure would be a dominant factor for the frequency effect observed under immersed NaCl environment at frequencies ranged from 15 to 0.5 Hz. However, fatigue crack growth rates at frequencies lower than 0.05 Hz were higher than those at frequencies higher than 0.5 Hz. The accelerated fatigue crack growth rates at frequencies lower than 0.05 Hz would be attributed to the corrosion attack at the crack tip.

• 出版日期2011-3-15