Fatigue Crack Propagation Behavior of AZ61 Magnesium Alloy under Controlled Cathodic Potential

Abstract:

In the present study, fatigue crack propagation (FCP) tests on Mg alloy, AZ61, were performed in 3% NaCl solution. The cathodic potential was controlled to achieve the hydrogen charged condition without anodic dissolution to figure out the effect of hydrogen on FCP behavior. The cathodic potential was set to be-3.0V, which corresponds to the immunity region without corrosion reaction based on Pourbaix diagram of Mg. The FCP rates were accelerated under hydrogen charged condition compared to those in dry air. Magnesium hydrides, MgH₂, were not detected along the crack wake in the measurement by X-ray Diffraction (XRD) method, suggesting that the acceleration could be attributed to the diffusion of hydrogen atoms.

• Periodical: Advanced Materials Research (Volumes 891-892)
• Pages: 917-922
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.891-892.917
• Online since: March 2014
• Authors: Tomonori Taniguchi*, Yoshihiko Uematsu, Yuji Hatano, Toshifumi Kakiuchi, Masaki Nakajima, Yuki Nakamura
• Keywords: Crack Propagation, Environment, Hydrogen Charge, Hydrogen Embrittlement, Magnesium Alloy

References

[1] Uematsu, Y, Kakiuchi, T, Nakajima, M, Nakamura, Y, Miyazaki, S, Makino, H, Fatigue crack propagation of AZ61 magnesium alloy under controlled humidity and visualization of hydrogen diffusion along the crack wake, International Journal of Fatigue, August (2013).

DOI: 10.1016/j.ijfatigue.2013.08.014

[2] ASTM E647-81: Standard Test Method for CONSTANT-LOAD-AMPLITUDE FATIGUE CRACK GROWTH RATES ABOVE 10-8m/CYCLE, Annual Book of ASTM Standard, Section 3.

[3] B. Bogdanović, A. Ritter, B. Spliethoff, K. Straβburger, A process steam generator based on the high temperature magnesium hydride/magnesium heat storage system, International Journal of Hydrogen Energy, Volume 20, Issue 10, October 1995, 811-822.

DOI: 10.1016/0360-3199(95)00012-3