What is it about?
The test data shows that in the transition region from short to long crack growth, the crack growth rate appears as a fluctuation form with acceleration following deceleration. A quasi harmonic function is constructed to model the fatigue crack growth in the transition region, and the result indicates that such function is suitable to describe the crack growth behavior.
Featured Image
Why is it important?
A metallographic analysis with respect to microscopic observation for the specimen’s surface suggests that the wave period, that is, a step length of a cycle fluctuation from acceleration to deceleration on the crack growth rate curve is agree well with the intrinsic scale of grain size, which indicates that in the transition region from short to long crack growth, grain boundary plays a dominant role in crack growth rate.
Perspectives
In the transition region from short to long crack growth, the stress intensity factor range is still lower than the fatigue crack growth threshold ΔKth, the effect of microstructure, such as grain size, grain boundary, secondary phase particle, and inclusion ahead of the crack tip, and the effect of crack closure on crack growth behavior should be considered.
Rongguo Zhao
Xiangtan University
Read the Original
This page is a summary of: Research on Transition from Short to Long Fatigue Crack Propagation of GH4133B Superalloy Used in Turbine Disk of Aero-Engine, Key Engineering Materials, July 2016, Trans Tech Publications,
DOI: 10.4028/www.scientific.net/kem.697.664.
You can read the full text:
Contributors
The following have contributed to this page
