The good, the bad and the ugly polishing: Effect of abrasive size on standardless EDS analysis of Portland cement clinker's calcium silicates

Vincent Thiery; Emmanuel Dubois; Séverine Bellayer

doi:10.1016/j.micron.2022.103266

The good, the bad and the ugly polishing: Effect of abrasive size on standardless EDS analysis of Portland cement clinker's calcium silicates

Micron. 2022 Jul:158:103266. doi: 10.1016/j.micron.2022.103266. Epub 2022 Mar 30.

Authors

Vincent Thiery¹, Emmanuel Dubois², Séverine Bellayer³

Affiliations

¹ IMT Nord Europe, Institut Mines-Télécom, Centre for Materials and Processes, F-59000 Lille, France; Univ. Lille, Institut Mines-Télécom, LGCgE - Laboratoire de Génie Civil et géo Environnement, F-59000 Lille, France. Electronic address: vincent.thiery@imt-nord-europe.fr.
² Univ. Lille, CNRS, Centrale Lille, Junia, Université Polytechnique Hauts-de-France, UMR 8520 - IEMN, - Institut d'Electronique de Microélectronique et de Nanotechnologie, F-59000 Lille, France.
³ Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 - UMET - Unité Matériaux et Transformations, F-59000 Lille, France.

PMID: 35427881
DOI: 10.1016/j.micron.2022.103266

Abstract

Standardless Energy dispersive spectroscopy (EDS) on polished samples of Portland cement clinker is routinely performed both for unhydrated phases as well as in cement pastes. Typically, the calcium to silica ratio is investigated. EDS analyses are highly dependent on the polishing quality of the sample. It is thus worth studying the Ca/Si ratios of cement phases in a clinker since they can be used as a reference. Indeed, alite (Ca₃SiO₅ or C₃S in cement chemistry notation) and belite (Ca₂SiO₄ or C₂S) should have an atomic Ca/Si ratio of 3 and 2, respectively. EDS carried out under the scanning electron microscope (SEM) is routinely used on polished samples to assess the composition of such phases. In the present study, Ca/Si ratios are investigated on a commercial clinker polished at various steps (6, 3, 1 and 0.25 µm diamond pastes, 0.05 µm alumina). All along the polishing process, ratios are coherent with theoretical ones and with the reference ones obtained by electron probe microanalysis (EMPA) in the present study.

Keywords: Electron Probe Microanalysis; Optical microscopy; Optical profilometry; Polishing; Portland cement clinker; Scanning electron microscopy and microanalysis.