Microstructure and Fatigue Characteristic of AM60B Magnesium Alloy

Metals

Farid Taheri¹  You Lu² 

[1] Department of Civil and Resource Engineering, Dalhousie University, 1360 Barrington Street, PO Box 15,000 Halifax, NS B3H 4R2, Canada;

关键词: AM60B magnesium alloy;    microstructure;    cold temperature;    elevated temperature;    fatigue crack growth rate;   

DOI  :  10.3390/met2040411

来源: mdpi

【 摘 要 】

This paper summarizes and reviews the findings of our research on AM60B magnesium alloy conducted in past 8 years. It essentially covers three categories: microstructural study, environmental effect, and fatigue crack growth rate of AM60B. The experimental and numerical studies on the influence of casting defects on this particular material’s properties are reviewed in the first part. It has been shown that the non-uniform solidification of the casting results in variations of the microstructure in different layers (skin and core) of the alloy which affects the mechanical properties in those regions. Moreover, the influence of microstructure on fatigue crack initiation and propagation response of the alloy is presented. The influence of several casting defects on the failure mechanism of the material are also numerically analyzed and discussed. The influence of elevated and cold temperatures on the fatigue response of the alloy is reviewed in the second part. Our findings show that the temperature does not have a significant effect on the number of cycles to failure. However, but at some stress level, this effect cannot be dismissed. The fatigue crack growth rate (FCGR) response of the alloy at a wide range of stress ratios is also investigated in the last part. The FCGR of the alloy showed a noticeable dependency on the stress ratio. A model is proposed for estimating the FCGR of the alloy, which could provide a good prediction of alloy’s FCGR over a wide range of negative and positive stress ratios. The integrity of the new model is also compared against other models. Finally, the influence of compressive loading on fatigue life of the specimens under constant and random amplitude cyclic loading is investigated experimentally.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.