Investigation of environmental effects on the fatigue properties of metallic nanostructures

Issued as final reportThe research activities of this EAGER grant focused on the development of an experimental technique dedicated to measuring the fatigue properties of nanomaterials, specifically nanocrystalline metallic nanobeams. This MEMS-based nanotensile testing setup can be used to measure the fatigue properties of nanocrystalline nanobeams (fatigue life, cyclic stress-strain curves, transient behavior). Fatigue tests can be performed for a wide range of maximum applied stresses and strains, frequencies (up to ~0.25-1Hz with the thermal-actuator-based MEMS devices), and environment. While the fatigue test presented in this report was performed in laboratory air, future tests can be performed in an environmental chamber to assess the influence of temperature and humidity on the fatigue properties. Last but not least, the same experimental setup can be used to perform quantitative in-situ TEM tests, using an electrical biasing TEM holder.National Science Foundation (U.S.