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Investigation of surface and thermogravimetric characteristics of carbon‐coated iron nanopowder
Author(s) -
Manchili Swathi K.,
Wendel Johan,
Cao Yu,
Hryha Eduard,
Nyborg Lars
Publication year - 2020
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.6878
Subject(s) - x ray photoelectron spectroscopy , thermogravimetry , iron oxide , materials science , scanning electron microscope , oxide , thermogravimetric analysis , carbon fibers , auger electron spectroscopy , analytical chemistry (journal) , chromium , chemical engineering , metallurgy , chemistry , inorganic chemistry , composite material , engineering , physics , chromatography , composite number , nuclear physics
Demand for high‐density press and sinter components is increasing day by day. Of the different ways to improve the sinter density, the addition of nanopowder to the conventional micrometer‐sized metal powder is an effective solution. The present investigation is aimed at studying the surface chemistry of iron nanopowder coated with graphitic carbon, which is intended to be mixed with the conventional iron powder. For this purpose, iron nanopowder in the size range of 30 nm to submicron (less than 1 micron) was investigated using thermogravimetry at different temperatures: 400°C, 600°C, 800°C, 1000°C, and 1350°C. The X‐ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and high‐resolution scanning electron microscopy (HR‐SEM) were used for characterizing the powder as well as samples sintered at different temperatures. The presence of iron, oxygen, carbon, chromium, and zinc were observed on the surface of the nanopowder. Iron was present in oxide state, although a small metallic iron peak at 707 eV was also observed in the XPS spectra obtained from the surface indicating the oxide scale to be maximum of about 5 nm in thickness. For the sample treated at 600°C, presence of manganese was observed on the surface. Thermogravimetry results showed a two‐step mass loss with a total mass loss of 4 wt.% when heated to 1350°C where the first step corresponds to the surface oxide reduction.