Daria Sidorenko

Nanocomposites for Machining Tools

Machining tools are used in many areas of production. To a considerable extent, the performance characteristics of the tools determine the quality and cost of obtained products. The main materials used for producing machining tools are steel, cemented carbides, ceramics and superhard materials. A promising way to improve the performance characteristics of these materials is to design new nanocomposites based on them. The application of micromechanical modeling during the elaboration of composite materials for machining tools can reduce the financial and time costs for development of new tools, with enhanced performance. This article reviews the main groups of nanocomposites for machining tools and their performance.

STRUCTURE AND PROPERTIES OF DYSPROSIUM TITANATE POWDER PRODUCED BY THE MECHANOCHEMICAL METHOD

The paper studies the structure and basic physical and chemical properties of titanate dysprosium powders produced by mechanochemical synthesis from the low-temperature modification of titanium oxide and modification of dysprosium oxide using X-ray diffraction methods (XRD), scanning electron microscopy, Raman spectroscopy (Raman spectra), transmission electron microscopy, and chemical analyz. Based on XRD it was found that complete conversion of initial oxides into X-ray amorphous dysprosium titanate (Dy 2 TiO 5 ) occurs during mechanical treatment of the mixture for 30–60 min. Microelectron-diffraction pattern of Dy 2 TiO 5 powders produced by mechanical synthesis has a ring-shaped structure with a certain amount of crystalline phase inclusions, which is typical for an X-ray amorphous phase. Dysprosium titanate powder produced by the induction melting method has a regular cubical lattice with a parameter 3,4 A.

Development of a Next Generation of Diamond Tools Based on Superhard Materials with a Nanomodified Binder for Steel and Cast Iron Machining

The possibility of using binders of the Next100 type alloyed with nickel and modified with WC, ZrO2, and hBN nanoparticles for fabricating a cutting tool based on superhard materials and intended for steel and cast iron machining is shown. It is established that alloying the binder with nickel makes it possible to increase its impact viscosity by a factor of 2.5 and substantially improve the resistance of tool segments during operation. An increase in binder strength by 100–150 MPa and hardness by 5–7 HRB is provided due to the introduction of WC, ZrO2, and hBN into it. The adhesion of cubic boron nitride to a binder increases in the presence of WC nanoparticles. The optimal ratio of diamond single crystals and cubic boron nitride in a working layer, at which maximal service characteristics of the tool are attained, is determined to be 75: 25. The formation of nanoclusters of amorphous boron at the interface of cubic boron nitride and a binder and dissolution of a small amount of nitrogen in binder components during hot compaction are revealed.