Corrosion fatigue of a 2024-T3 aluminum alloy in the short crack domain

✍ Scribed by K. -C. Wan; G. S. Chen; M. Gao; R. P. Wei

• Publisher: Springer Netherlands
• Year: 1995
• Tongue: English
• Weight: 271 KB
• Volume: 69
• Category: Article
• ISSN: 1573-2673
• DOI: 10.1007/bf00034770

✦ Synopsis

It is well accepted that the steady-state fatigue crack growth rates of long cracks depend uniquely on AK for a fixed load ratio R and test environment. Anomalous growth behavior of short cracks in either inert or deleterious environments that has been reported [1-7], however, calls into question the validity of using only long-crack results in evaluating the service life of a structural component and argues for the need for considering the effects of crack size. Crack-size effects have been extensively studied from the perspectives of mechanical, metallurgical and chemical principles. Microstructurally and mechanically short cracks [1-3] are associated with the influences of fine-scale microstructure, the limitation of continuum mechanics (or LEFM-linear elastic fracture mechanics), or crack closure. Chemically short cracks [4][5][6][7], on the other hand, normally extend to longer lengths and are attributed to the differences in local crack-tip chemistry (e.g., pH, [Oz], potential) between the long and short cracks and also, perhaps, from the bulk solution. The objective of this study is to explore the effect of crack size in various environments and to identify the key variables that affect crack growth behavior. The crack size investigated herein was chemically short but microstructurally and mechanically long.