First use of data fusion and multivariate analysis of ToF‐SIMS and SEM image data for studying deuterium‐assisted degradation processes in duplex steels

Abstract

a Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and high-resolution scanning electron microscopy are wellacknowledged tools in materials characterization. The ability to map chemical species on the surface of an investigated sample with often low mass detection limits makes ToF-SIMS an essential tool in fields where many question marks concerning degradation processes and damage mechanisms exist. The aim of this paper is to describe the power of data fusion of ToF-SIMS and high-resolution scanning electron microscopy results employing computational methods for multivariate data analysis such as principal component analysis. As a case study the investigation of hydrogen distribution in an artificially charged duplex stainless steel microstructure is presented aiming on a better understanding of hydrogen embrittlement.

Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) imaging of deuterium assisted cracking in a 2205 duplex stainless steel micro-structure

“…matrix effects) therefore it is necessary to pre-process the raw data before PCA in order to cancel bias related to these effects [28]. Details for PCA and data fusion have been reported elsewhere [14,29].…”

“…The sputter time was 5 min for surface cleaning and 1 min for co-sputtering after every data acquisition. Cs þ co-sputtering was used to enhance the negatively charged secondary ion yield [14]. Imaging of the deuterium distribution was carried out by scanning a field-of- Imaging for phase distinction has been made in the positive mode with the sample at room temperature.…”

“…In the past few years, Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) has been shown to be a powerful tool to precisely map the distribution of hydrogen, along with other elements, in steel microstructures [8,[12][13][14], delivering data from the very surface (with a surface sensitivity below 1 nm) [15]. In addition to a literature survey on SIMS experiments related to hydrogen effects given elsewhere by the authors [12], highly resolved imaging examples are shown by Tarzimoghadam et al [13] who utilized SIMS for the investigations of hydrogen assisted degradation in a Ni based superalloy.…”

“…State-of-the-art ToF-SIMS instruments may provide precise element and phase mappings with a lateral resolution below 100 nm [18], enabling imaging of the microstructure and analysis of its phase dependent chemical composition [13,14,19]. Recently, ToF-SIMS image analysis has substantially been improved by multivariate analysis (MVA) of image data and by data fusion of the chemical and topographic information [14]. For these reasons, ToF-SIMS as the primary analysis tool used has been combined with high resolution scanning electron microscopy (HRSEM).…”

Application of pan-sharpening algorithm for correlative multimodal imaging using AFM-IR

“…This approach can be used in the case when the functional relationship between two images (e.g., how change of one parameter is related to the change of the second one) is not precisely know a priori and needs to be established during the analysis. However, data fusion of mass spectrometry data with microscopy data that has already been demonstrated [28][29][30] is prone to the generation of reconstruction artifacts. Specifically, the image formation mechanism in a secondary electron or optical image is drastically different from chemically-sensitive spectroscopical channels, so the correlation established within data fusion process implies a relationship between two channels that are not physically linked together.…”