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The study determines the parameters of defects generated in a roller bearing used in the link of a mould oscillating mechanism that makes part of a continuous billet-casting machine. The evolution of such defects is described from the perspective of scale levels of deformation and fracture. The studied wear behaviour in the bearing corresponds to false brinelling; the raceways suffer the formation of grooves having the bottom with folded morphology. The mechanisms of deformation and wear of the bearing were analysed using multi-level approach, i.e. at macro-level, from the perspective of the mechanics of a deformable rigid body, at meso-level II, implementing tribological approaches, and at meso-level I, using the methods of indentation, three-dimensional profilometry and fractography.

In order to find an effective solid lubrication filler for the composites based on ultra-high molecular weight polyethylene, tribotechnical properties of UHMWPE and its blends with calcium stearate (С36Н70СаО4, CS) under dry friction, boundary lubrication and abrasion were studied. It is demonstrated that wear rate of UHMWPE-CS compositions under dry sliding friction decreases by more than 4 times as compared to pure UHMWPE while the mechanicals properties do not change substantially. Under abrasion conditions the wear rate of the stated composites rises with the increased content of the filler. The optimal filler weight fraction is determined in terms of ensuring maximum wear resistance. The wear mechanisms of UHMWPE-based polymer compounds with a solid lubrication filler under dry sliding friction conditions and abrasion are discussed.

Shock fracture mechanisms of different scales were investigated on epoxy composite materials reinforced with silicon carbide microparticles of different concentrations. It is shown that the high heterogeneity of the epoxy composites at different structural scales is one of the factors responsible for their physical and mechanical properties. Under dynamic loading, the material reveals a developed structural scale hierarchy which provides self-consistent deformation and fracture of the material bulk with the lead of rotational deformation modes. As a result, microcracks develop due to low shear strain limited in addition by reinforcing particles. At the start of a main crack, microscale mechanisms dominate, whereas the propagation of its front is governed by macroscale fracture mechanisms.

Tribological characteristics of ultrahigh-molecular-weight polyethylene (UHMWPE)-based compositions with graphite and molybdenum disulfide are studied under conditions of dry friction, boundary lubrication, and abrasive wear. It is shown that, under dry sliding friction, the wear rate of UHMWPE-graphite and UHMWPE-MoS2 polymer compositions is halved as compared to that of pure UHMWP, while their mechanical characteristics change only slightly. Under the conditions of abrasive wear, the wear resistance of these composites increases by 1.3–1.5 times. Concentrations of the fillers, which are optimum for improving the wear resistance, are determined. The supramolecular structure and the topography of worn surfaces of the UHMWPE compositions with various concentrations of the fillers are examined. A comparative analysis of the wear resistance of the composites under conditions of dry friction and lubrication is carried out. Mechanisms of the wear of the UHMWPE-graphite and UHMWPE-MoS2 polymer compositions under conditions of dry sliding friction and abrasive wear are discussed.

Results of a quantitative study of multilevel, hierarchically organized localization of shear deformation attendant to compression of a Ni3Fe single crystal are presented. A statistical analysis of the results is performed and values of the characteristics of localization of shear deformation at selected scale-structure levels are obtained.

The structural modification on friction with boundary lubrication is considered for 110Γ13 steel with and without impact ultrasound treatment. The change in fine structure of the surface and near-surface layers is analyzed on the basis of transmission electron microscopy. The differences in wear of the treated and untreated samples are interpreted.

The paper presents the results of static and cyclic tensile tests and alternate cyclic bending tests of 12Cr1MoV specimens in the initial state and after surface nanostructuring with a Zr+ ion beam. Examination by optical and scanning electron microscopy and interference profilometry revealed differences in the formation of the deformation relief and in the character of cracking of the modified surface layer. The changes occurring in the modified surface layer were estimated by nanoindentation, X-ray analysis, and fractography. The nanostructure formed in the treated surface layer was analyzed by transmission electron microscopy. The difference in deformation is interpreted using the multiple cracking concept. The effect of substantial enhancement of fatigue strength is associated with retarded plastic deformation and fatigue crack propagation in the modified surface layer.

The structural modification and change of wear resistance on friction with boundary lubrication is considered for 110Γ13 steel with and without impact ultrasound treatment. The deformational relief formed on the lateral surface of the samples in compression and in frictional loading is found to be the same. On that basis, the factors responsible for the change in wear resistance are discussed.

It is established that different structure of slip dislocation at the end of the linear hardening stage results in different distribution of dislocation charges in the volume of a single crystal. In the alloy with a near atomic order the slip of single dislocations leads to formation of planar structures—layers with the excess density of dislocations. In the alloy with long-range atomic order the slip of superdislocations brings the formation of the system of parallel rod-like charged dislocation linking.

In order to compare effectiveness of adding solid lubricating fillers for polymeric composites based on ultra-high molecular weight polyethylene (UHMWPE) with graphite, molybdenum disulfide and polytetrafluoroethylene, their tribotechnical characteristics under dry friction, boundary lubrication and abrasive wearing were investigated. The optimal weight fractions of fillers in terms of improving wear resistance have been determined. The supramolecular structure and topography of wear track surfaces of UHMWPE-based composites with different content of fillers have been studied.

A cyclic tension and alternating bending tests of 12Cr1MoV steel specimens in as-supplied state and after surface nanostructuring by Zr+ ion beam have been carried out. Distinctions in formation of strain induced relief, as well as the cracking pattern of modified surface layer are illustrated by methods of optical microscopy and interferential profilometry. Changes to occur in subsurface layer are characterized by means of nanoindentation and fractography observation of fracture surfaces. The description of differences of deformation behavior is performed with use of the multiple cracking concept.

Influence of surface strengthening by nanostructuring surface layer being implemented by ultrasonic impact treatment and deposition of high-strength nanostructured coating was investigated under friction of 30CrMnSi2Ni steel specimens at boundary lubrication. It is shown that formation of uniform nanostructured state in thin subsurface layer with gradient changing of strength with depth of the specimens by the ultrasonic treatment provides increase of wear-resistance of the specimens. This effect is intensified in case of subsequent deposition of the nanostructured TiAlN coating that make it possible to fixes the formed nanostructured state.

The study of the deformation relief of aluminum monocrystals oriented for a single slip has been carried out using methods of optical and interference microscopy. It has been established that in the volume of a single crystal several macrofragments are formed, differing in size and direction of shear. Reasons for formation of two systems macrobands of shear are identified. It has been shown that formation of the deformation relief in the investigated crystal occurs at three scale-structural levels.