S. N. Grigor’ev

Automated thermal-strength calculations of ceramic cutting plates

An automated system for thermal-strength calculations of ceramic cutting plates is proposed. This system is based on microstructural and mathematical models and provides information regarding the thermal state and stress-strain state of cutting plates under the action of external loads. The structural nonuniformity of the ceramic is taken into account.

Effect of the pulsed laser deposition conditions on the tribological properties of thin-film nanostructured coatings based on molybdenum diselenide and carbon

The structural state and tribological properties of gradient and composite antifriction coatings produced by pulsed laser codeposition from MoSe2(Ni) and graphite targets are studied. The coatings are deposited onto steel substrates in vacuum and an inert gas, and an antidrop shield is used to prevent the deposition of micron-size particles from a laser jet onto the coating. The deposition of a laser jet from the graphite target and the application of a negative potential to the substrate ensure additional high-energy atom bombardment of growing coatings. Comparative tribological tests performed at a relative air humidity of ∼50% demonstrate that the “drop-free” deposition of a laser-induced atomic flux in the shield shadow significantly improves the antifriction properties of MoSex coatings, decreasing the friction coefficient from 0.07 to 0.04. The best tribological properties, which combine a low friction coefficient and high wear resistance, are detected in drop-free MoSex coatings additionally alloyed with carbon (up to ∼55 at %) and subjected to effective bombardment by high-energy atoms during growth. Under these conditions, a dense nanocomposite structure containing the self-lubricating MoSe2 phase and an amorphous carbon phase with a rather high concentration of diamond bonds forms.

Stress-strain state of a coated nitride-ceramic tool

The influence of coatings on the stress-strain state of nitride-ceramic cutting plates is considered. The thermal and stress state of such plates may be regulated by adjusting the coating properties.

Stress Inhomogeneity in a Ceramic Surface Layer under Action of an External Load. Part 2. Effect of Thermal Loading

Results are provided for a comprehensive study of stress inhomogeneity in a ceramic surface layer based on zirconium dioxide under action of thermal loading. High stress inhomogeneity is revealed in ceramic structural elements. A requirement is noted for considering stress inhomogeneity in describing a wear and failure mechanism, and also in designing objects of this ceramic for prescribed operating conditions.

Influence of thermal loads on the stress-strain state of aluminum-oxide ceramic cutting plates

The influence of thermal loads on the stress-strain state of oxide-ceramic cutting plates is investigated; in the analysis, the nonlinear properties of aluminum oxide and gray iron are taken into account. Requirements are formulated on the properties of aluminum-oxide cutting plates.

Stress Inhomogeneity in a Ceramic Surface Layer Under Action of an External Load. Part 1. Effect of Complex Mechanical Loading

First results are provided for a comprehensive study of stress inhomogeneity in a ceramic surface layer. The stress-strained state of a ceramic surface layer based on zirconium dioxide under the action of a complex mechanical load is studied. High stress inhomogeneity is revealed in ceramic structural elements. A requirement is noted for considering stress inhomogeneity in describing a wear and failure mechanism, and also in designing objects of this ceramic for prescribed operating conditions.

Effect of a TiC Coating on the Stress-Strain State of a Plate of a High-Density Nitride Ceramic Under Nonsteady Thermoelastic Conditions

An original method is presented to obtain relations which describe how the thickness and thermal conductivity of a TiC coating are related to the temperatures, displacements, and stresses in a nitride ceramic plate under nonsteady thermoelastic conditions. It is shown that the stress-strain state of parts made of high-density ceramics can be controlled under such conditions by the application of coatings.

Effect of Titanium Nitride Coating on Stress Structural Inhomogeneity in Oxide-Carbide Ceramic. Part 4. Action of Heat Flow

The effect of a titanium nitride coating on stress structural inhomogeneity in oxide-carbide ceramic under action of heat flow is studied. A considerable effect of a coating on properties determining stress structural inhomogeneity within ceramic is revealed. A requirement is noted for considering stress structural inhomogeneity in designing objects from oxide-carbide ceramic with a coating.

Effect of Titanium Nitride Coating on Stress Structural Inhomogeneity in Oxide-Carbide Ceramic. Part 3. Action of Distributed Force Load

The effect of a titanium nitride coating on stress structural inhomogeneity in oxide-carbide ceramic under action of a distributed force load is studied. The effect of a coating on properties determining stress structural inhomogeneity within ceramic is established. A requirement is noted for considering stress structural inhomogeneity in designing objects from oxide-carbide ceramic with a coating.

Effect of Titanium Nitride Coating on Stress Structural Inhomogeneity in Oxide-Carbide Ceramic. Part 5. A Combined Load Operates1

The effect of a titanium nitride coating on stress structural inhomogeneity in oxide-carbide ceramic under action of a combined load is studied. A considerable effect of a coating on properties determining stress structural inhomogeneity within ceramic is revealed. A requirement is noted for considering stress structural inhomogeneity in designing objects from oxide-carbide ceramic with a coating.