Kolli R Prakash
Department of Materials Science and Engineering, University of Maryland, 2144 Chemical and Nuclear Engineering Bldg., #090, College Park, MD 20742-2115 USA.
Adv Struct Chem Imaging. 2017;3(1):10. doi: 10.1186/s40679-017-0043-4. Epub 2017 Feb 22.
Residual hydrogen (H) gas in the analysis chamber of an atom probe instrument limits the ability to measure H concentration in metals and alloys. Measuring H concentration would permit quantification of important physical phenomena, such as hydrogen embrittlement, corrosion, hydrogen trapping, and grain boundary segregation. Increased insight into the behavior of residual H gas on the specimen tip surface in atom probe instruments could help reduce these limitations. The influence of user-selected experimental parameters on the field adsorption and desorption of residual H gas on nominally pure copper (Cu) was studied during ultraviolet pulsed laser atom probe tomography. The results indicate that the total residual hydrogen concentration, , in the mass spectra exhibits a generally decreasing trend with increasing laser pulse energy and increasing laser pulse frequency. Second-order interaction effects are also important. The pulse energy has the greatest influence on the quantity , which is consistently less than 0.1 at.% at a value of 80 pJ.
原子探针仪器分析室中的残余氢气（H）限制了测量金属和合金中氢浓度的能力。测量氢浓度将有助于量化重要的物理现象，如氢脆、腐蚀、氢俘获和晶界偏析。深入了解原子探针仪器中试样尖端表面残余氢气的行为，有助于减少这些限制。在紫外脉冲激光原子探针层析成像过程中，研究了用户选择的实验参数对名义纯铜（Cu）上残余氢气的场吸附和解吸的影响。结果表明，质谱图中的总残余氢浓度随激光脉冲能量和激光脉冲频率的增加总体呈下降趋势。二阶相互作用效应也很重要。脉冲能量对总量的影响最大，在80 pJ时，该值始终小于0.1原子百分比。
