OBRABOTKAMETALLOV MATERIAL SCIENCE Том 23 № 3 2021 EQUIPMEN . INSTRUM TS Vol. 7 No. 3 2025 and crushing methods, such as jaw, ball, cone, rod, roller (roller press), and rotary crushers [10–16]. If sorting the crushed grains by shape is required, they undergo additional treatment [17–21]. The most common quantitative criterion for the shape of abrasive grains is the shape factor, defined as the ratio of the length l of the grain projection on a horizontal plane to the width b. Length is defined as the largest distance between perimeter points (the maximum Feret diameter). Width is calculated as the sum of the maximum distances from the length line to the left and right sides of the perimeter, divided by the length line (ISO 9276-6-2008, GOST R 70336-2022). In effect, the grain projection is inscribed in a rectangle where the longest side corresponds to the length of the grain, and the shortest side corresponds to the width. The crushing and grinding methods of abrasive materials significantly affect the shape and properties of the resulting particles. For example, studies have shown that when crushing corundum using roller, cone, and ball crushers, a ball crusher yields the greatest isometricity [11, 12]. The influence of grinding methods on the geometric parameters and shape of grains within the current technological process for producing abrasive materials at JSC Volzhsky Abrasive Plant, a leading enterprise in the industry, is of particular interest. The relevance of this research is further supported by the fact that JSC Volzhsky Abrasive Plant is “the only producer of silicon carbide in Russia and the largest in Europe” [22]. Silicon carbide is used to manufacture grinding powders and micro-powders, a wide range of abrasive tools, refractories, and specialized products. These diverse applications, encompassing abrasive machining of various parts and the production of a wide range of items, preclude the establishment of uniform requirements for geometric parameters and grain shape. Consequently, it is essential to consider the specific characteristics of the machined surface and the properties of the target product. For example, in cutting operations where the objective is to increase productivity, cutting wheels made of grinding powders with a shape factor kf = l/b = 2.2 are employed, where l and b represent the length and width of the grain, respectively. Conversely, if minimizing abrasive tool consumption is the primary concern, isometric grains with a shape factor of l/b = 1.3 are preferred [23]. To grind silicon carbide, the plant employs various methods, equipment, and processing parameters that influence the geometric characteristics and properties of the grains. Roller press grinding and rotary grinding are among the most common methods implemented at JSC Volzhsky Abrasive Plant. Grain sizes exhibit significant variation. For instance, GOST R 52381-2005 specifies a range of grain and fraction sizes spanning from 4,750 μm, to 45 μm. Furthermore, based on grain composition, grinding powders are categorized into 30 grain sizes, each containing 5 distinct fractions. The purpose of the paper is to investigate the effect of roller press grinding and rotary grinding of black silicon carbide, as implemented at JSC Volzhsky Abrasive Plant, on the grain shape factor of fraction samples. Tasks: – to determine the distribution patterns of black silicon carbide grain shape factors, along with the geometric parameters influencing them (grain length and width); – to analyze correlation and regression relationships between grain shape factors and geometric parameters; – to identify trends in geometric parameters of grains within fraction samples produced by roller press grinding and rotary grinding. Research Methodology The input materials for roller press and rotary grinding were produced under identical conditions following the current technological process. Black silicon carbide feedstock was sequentially processed using a cone crusher and a rod mill. Following drying, a portion of the abrasive material was ground using a roller press, while the remaining portion was subjected to rotary grinding. The PVI 800/150 roller press used at JSC Volzhsky Abrasive Plant is characterized by: adjustable hydraulic pressure applied to only one roll, which avoids over-grinding; and material crushing within an
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