High-temperature wear-resistant materials based on silicon nitride

Abstract

Rolling bearing is one of the most demanding assembly units and in many respects defines operational behavior of current aerospace engineering, oil and gas transfer facilities, output turbines, heat-and electrogenerating sets, nuclear reactor turbines, land and water transport, pump blocks. Ceramic materials based on silicon nitride exhibit high hardness and wear resistance and still have less density as compared with metals, which makes it possible to attain service life at high temperatures and at high revolutions (~ 100 thousands rpm and more), in corrosion environment, and where long service life, low noisiness and high positional accuracy are required. Hot-pressed silicon nitride possesses maximum strength in relation to other ceramic materials, which is why it appears to be particularly promising for use in rolling bearings. A wide range of ceramic materials based on silicon nitride has been developed. Hotpressed materials OTM-906 and OTM-914 correspond in composition, structure and properties to the best in the world analogues of bearing ceramic materials of NC-101C and NBD-200 grades. A composite material in Si 3 N 4 -BN system has been developed. The lack of chemical interaction between silicon nitride and boron nitride having fine self-lubricating properties determines the possibility for the development of bearing retaining rings with selective boron nitride distribution for the enhancement of self-lubrication effect. The results of an investigation into tribological behavior of the developed materials and the results of the ceramic rolling bearings testing are presented. Keywords: silicon nitride, boron nitride, hot pressing, rolling bearing, bearing cage, wear resistance, back-to-back endurance She is engaged in research and development activities on high-temperature monolithic and composite materials based on silicon nitride, with predetermined microstructure and controlled properties, and in hot-pressing technology for the manufacture of structural articles (thermal-, wear-and shock-resistant articles for use in purpose-built equipment and advanced gas-turbine engines). The main results of her research work are represented in 50 papers, including articles, patents and proceedings of Russian and international conferences.

Mechanochemical Phenomena during Fine Comminution of Clay Minerals for Ceramic Bricks and Roof-Tiles

“…Nowadays, ceramic items are normally produced with materials having submicron and nanoparticles [24][25][26][27][28]. The raw materials mined at the European ceramic brick and roof-tile plants usually contain considerable proportions of clay minerals, phyllosilicates, layered and amorphous silicate materials [29][30][31][32][33][34], and have submicron particles in different ratios with different specific surface area and grain size distribution.…”

Influence of Sintering Atmosphere and IG-017 Bio-Original Additives on Porosity of Ceramics Made from High Purity Al2O3 and SiO2 Powders

“…In our days the industry requires more and more low density and mechanically strong materials capable to work in high temperature environment. To satisfy these inquires more and more ceramics [1][2][3][4][5][6][7] and ceramic matrix composites [8,9] or cermets [10,11] are applied. To increase the wear resistance and live times of machine parts or machine tools very often hard ceramic coatings and ceramic based composites are used [12][13][14].…”

The Influence of Temperature on the Properties of ZrW2O8

“…One potential solution of this problem lies in the development of composite materials with an appropriate matrix and filler. The use of ceramics as a matrix is reasonable as they possess high mechanical strength, hardness and wear resistance while retaining its properties under high temperatures [1][2][3][4][5][6]. However, ceramics are known to display low toughness making them brittle enough for specific applications.…”