Measuring oxygen solubility in Ni grains and boundaries after oxidation using atom probe tomography

Poor oxidation resistance is a key contributor to material failure within extreme environments. Understanding oxygen solubility is important for computation aided design of new high strength, high-temperature oxidation resistant alloys. Oxygen solubility within pure metals, such as Ni, has been studied using a multitude of techniques, but Atom Probe Tomography (APT) has not been used for such a measurement to date. APT is the only technique offering both a high chemical sensitivity (<10 ppm) and resolution (<1 nm) allowing for a composition measurement within nms of the oxide/metal interface. APT was employed to measure the oxygen content at different depths from the oxide/metal interface as well as grain boundaries for a high and low purity Ni sample oxidized at 1000 degrees C for 48 h. The results reveal <10 s of ppm oxygen solubility within Ni metal at all depths and 100 s of ppm oxygen within GBs. (C) 2021 The Authors. Published by Elsevier Ltd on behalf of Acta Materialia Inc.

Automated summary

Understanding the oxygen solubility in materials is crucial for designing oxidation resistant alloys. Atom Probe Tomography (APT) provides high chemical sensitivity and resolution, revealing the oxygen content within Ni metal and grain boundaries.