Investigation on nanoindentation and TOF-SIMS applications in the hydrogen and oxygen absorption behavior of Zr-Sn-Nb alloys

This paper focuses on nanoindentation and TOF-SIMS (time-of-flight secondary ion mass spectrometry) small-scale test methods in the study of hydrogen absorption and oxygenation behavior analysis of Zr-Sn-Nb oxidized at 650°C -1200 °C. The CSM (Continuous Stiffness Method) test demonstrates the hardness fluctuations caused by element proliferation in post-high temperature oxidation microstructures. The deformation resistance ability of typical microstructures is as follows: β-Zr layer > α-Zr(O) layer > ZrO2 layer. In addition, hydrogen-induced softening occurred in steam-containing hydrogen conditions (HIT=2～3Gpa), compared to steam (HIT=5～16Gpa). The 1200℃ load-displacement curve demonstrates that the pop-in (or pop-out) effect exists in the Zr-Sn-Nb alloy, related to the influence of hydrogen charge, essentially to dislocation nucleation, winding, and movement. TOF-SIMS provides an effective method for small molecular chemical elements, such as H and O, while ZrO, ZrO2, ZrO2H, ZrO3H, OH, and O2 ions also be found. Based on these results, this study also hypothesizes the OH- dominated oxidation reaction equation.