Durability and exploitation performance of cutting tools made out of chromium oxide nanocomposite materials
In the engineering systems, even though the lifetime is prolonged, the maintenance cost increases accordingly when fault incurs [7] In order to reduce expenses, computer aided maintenance and reliability systems are often applied, as it was reported in case of conveyor belts [19] as well as computer simulation methods [13] In the context of Industry 4.0, Big Data gains increasing importance [8] Durability of cutting tools, especially during machining of hard materials, is a subject of many research works [16] When selecting proper cutting tool for the particular machining task, optimal durability is one of the requirements [1] One of research directions to prolong cutting tools lifetime is the formation of cutting edge microgeometry which is designed by special processes after grinding or after deposition of the thin layer [28] There are reports on various layers of nanoscale thickness, e.g. nanocrystalline Al2O3 layer deposited by MOCVD on cemented carbide cutting tools [24] In fact, 85% of all cemented carbide tools are coated [3] but also ceramic materials are coated in order to improve their performance and durability. For instance, Liu et al. proposed novel quaternary coating on the surface of silicon nitride ceramic cutting tool and investigated its dominant wear mechanism [18] In another reported study, Al2O3 was coated on the surface with CaF2 nanolayer by non uniform nucleation method, so the mechanical properties of ceramic tools coated with nano solid lubricant have been significantly improved [4] It was demonstrated also, that PVD coatings and ALD PVD hybrid coatings deposited on sialon tool ceramics performed better exploitative properties in comparison with a coating (Ti,Al)N obtained by the conventional method [26] However, any additional operation of coating, especially with nanolayers, generates increasing costs. Thus, another way to improve durability and performance of ceramic cutting tools is directed to its microstructure formation. It was reported that doping with a small amount of Eu2O3 decreases the bulk density and wear resistance of high alumina ceramics [17] Since ceramic matrix composites are outstanding in their ability to withstand high temperatures, in addition their hardness and wear resistance, carbon fiber ceramic matrix composites are applied, as well as ceramics armed with carbides, nitrides, oxides, and their combinations, including composites with carbon nanotubes and carbon nanofibers [5] This paper is devoted to the nanocomposite Cr2O3 materials produced by the activated electric field sintering procedure. As it will be demonstrated below, its fabrication is cheaper and exploitative properties are better than that of other ceramic cutting tools available in the market.
Eksploatacja i Niezawodnosc Maintenance and Reliability