NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
We employ periodic density functional calculations to explore the effect of cyclic tensile loading on the behavior of alumina in the threshold region of crack formation, i.e., where the crystal must choose between healing a defect through a uniform elastic strain of the material or creating two free surfaces. We find evidence for nanoscale fatigue when the alumina lattice is subjected to uniaxial tensile loading and unloading. It is likely that such atomic-scale fatigue impacts the durability of ceramics, since the highly ionic bonding requires near-ideal lattice structures in order to maintain cohesive strength.