Authors: V Nalladega S Sathish S Abburi M F X Gigliotti P R Subramanian
Publish Date: 2010/10/30
Volume: 42, Issue: 4, Pages: 1073-1088
Abstract
Nanostructured and ultra–finegrained metals and alloys are becoming of engineering interest However little is known about the influence of grain refinement on fatigue crack behavior In this study fatigue crack growth behavior and the key microstructural features controlling the fatigue fracture in nanocrystalline and ultra–finegrain nickel alloys processed using different techniques were investigated White light interference microscopy as well as the combination of atomic force microscopy AFM and ultrasonic force microscopy UFM were used to characterize the fractured surfaces of the metals The role of grain size on the fatigue crack growth resistance and the effect of fracture surface roughness on the crack growth rate were evaluated The combination of AFM and UFM is presented as a complementary tool to scanning electron microscopy in the fractography of metalsTwo of the authors MFXG and PRS would like to acknowledge M Gilhooly GE Global Research and P Dupree retired for their experimental support as well as Margaret Blohm Project Leader—Nanotechnology for supporting this research This effort was made possible by a research grant from GE Global Research to UDRI
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