SURFACE PROPERTIES OF DIAMOND GRINDING POWDERS OF THE AC250 BRAND OF DIFFERENT GRAIN SIZES

Abstract

The paper presents the results of the study of the surface properties of diamond grinding powders of the AC250 brand
with grain sizes of 630/500 and 500/400 (according to the normative documentation of Ukraine). The study of the structural and
sorption properties of the surface of the grinding powders was carried out by the volumetric method of nitrogen adsorptiondesorption
according to the standard procedure. It is shown that despite the larger size of the diamond crystals, the sample with
grain size of 630/500 has a larger specific surface area (0.21 and 0.18 m2/g, respectively) and a pore volume of 1.99 versus
1.75×10-4 ml/g, compared to the sample with grain size of 500/400. This result is due to the smaller average pore radius for the
sample with grain size of 630/500, compared to the sample with grain size of 500/400. At the same time, the studied samples
have a specific surface area approximately 50–70 times larger than the surface area of ideal diamond crystals of the
corresponding grain size, and increased hydrophilicity, which is the result of the presence of point defects in the surface layer
of the samples.