Micro-homogeneity studies of boron carbide powders

• Published in: Mikrochimica acta (1966) Vol. 173; no. 1-2; pp. 183 - 188
• Main Authors: Kadenkin, Alexander, Amberger, Martin, Fittschen, Ursula E. A., Broekaert, José A. C.
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.04.2011; Springer
• Subjects: Analysis; Analytical Chemistry; Carbides; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Exact sciences and technology; Fluorescence spectroscopy; Leaching; Microengineering; Nanochemistry; Nanotechnology; Original Paper; Powders; Spectrometric and optical methods; X-ray spectroscopy; ICP–OES; Micro-homogeneity; Boron carbide; TXRF; Impaction; Particle size; Impurity; Size; Atomic emission spectrometry; Inductive coupling plasma spectrometry; Powder; Boron; Sample holder; Emission spectrometry; Total reflection; Sampling; Measurement error; ICP-OES; Trace analysis; Optical spectrometry; Coupled method; Use; Impactor; Concentration; Digestion; Particle suspension; Droplet; Leaching; Nitric acid; Residue; Distribution; Laser; Aerosols; Parameter; X ray fluorescence spectrometry; Slurries; Carbides
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-011-0546-y

We have studied the micro-homogeneity of boron carbide powders by inductively coupled plasma optical emission spectrometry (ICP-OES) and total reflection X-ray fluorescence spectrometry (TXRF) using slurry sampling. To get information on the particle size distributions of the powders, the stabilized slurries of boron carbide powders were nebulized, the aerosols were transported into a Batelle impactor and the droplets were collected on the impactor stages bearing TXRF sample holders. In a first series of measurements, parameters of the impaction like the duration of the impaction and the use of glutinous substance on the sample holders were optimized. The different mass size fractions for industrial boron carbide powders were determined by weight measurements of the fractions collected on the different stages. The established particle size distributions were in the range of 0.5 to >16 μm and found similar to those determined by laser diffraction reported elsewhere. Analyses of the mass fractions by slurry sampling TXRF showed that Ca, Ti, Cr, Mn, Fe, Ni and Cu within the measurements errors were homogeneously distributed over the mass fractions between 0.5 and 4 μm and that their concentrations agreed with the bulk composition, as determined with ICP-OES subsequent to digestion. However, light underestimates were found at the 5 (Mn) up to 150 μg g −1 (Fe) level. Finally, boron carbide powders were washed out with nitric acid with different concentrations and leaching solutions and the residues were analyzed by ICP-OES and TXRF respectively. It is shown that up to 60% of the residual trace impurities in the powder studied can be removed by leaching with 34% ( v/v ) of nitric acid. Figure The trace element concentrations over different particle size fractions in boron carbide powders could be shown by total reflection x-ray fluorescence spectrometric measurements at the cascade impactor separated fractions not to vary too much over the different fractions.