E. A. Kolubaev

Analysis of acoustic emission during sliding friction of manganese steel

The process of acoustic emission during the sliding friction of X120Mn12 (DIN EN Standard) manganese steel has been studied. The coefficient of sliding friction has been determined in the absence of lubricants and the parameters of generated sound have been measured. A relationship between the acoustic emission spectrum and the friction coefficient is established.

General regularities of the microstructure formation during friction stir welding and sliding friction

A comparative metallographic analysis of the formation of the metal microstructure during sliding friction and friction stir welding is performed. It has been shown based on the example of a weld joint made of aluminum alloy fabricated by friction stir welding that the weld microstructure has all signs of the deformed layer of metal formed due to sliding friction, which is accompanied by the seizure of conjugated surfaces.

Time-frequency analysis of acoustic signals in the audio-frequency range generated during Hadfield’s steel friction

Time-frequency analysis of sound waves detected by a microphone during the friction of Hadfield’s steel has been performed using wavelet transform and window Fourier transform methods. This approach reveals a relationship between the appearance of quasi-periodic intensity outbursts in the acoustic response signals and the processes responsible for the formation of wear products. It is shown that the time-frequency analysis of acoustic emission in a tribosystem can be applied, along with traditional approaches, to studying features in the wear and friction process.

Effect of elastic excitations on the surface structure of hadfield steel under friction

The structure of the Hadfield steel (H13) surface layer forming under dry friction is examined. The deformation of the material under the friction surface is studied at a low slip velocity and a low pressure (much smaller than the yields stress of H13 steel). The phase composition and defect substructure on the friction surface are studied using scanning, optical, and diffraction electron microscopy methods. It is shown that a thin highly deformed nanocrystalline layer arises near the friction surface that transforms into a polycrystalline layer containing deformation twins and dislocations. The nanocrystalline structure and the presence of oxides in the surface layer and friction zone indicate a high temperature and high plastic strains responsible for the formation of the layer. It is suggested that the deformation of the material observed far from the surface is due to elastic wave generation at friction.

Subsurface deformation in copper single crystals during reciprocal sliding

AbstractThe deformation surface pattern generated on the faces of a copper single crystal loaded by a compression force and simultaneously sliding over the counterbody surface has been studied. The samples under study are copper single crystals with different orientations of the compression axis, which are grown by the Bridgman method. The study of the friction of single crystals with the orientations [110] and [

Non-Destructive Testing of Aluminum Alloys by Using Miniature Eddy-Current Flaw Transducers

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Effect of friction stir welding parameters on defect formation

11] has revealed that the shear systems whose action manifests itself on side faces are localized near the friction zones. The density of traces formed in this process decreases with the distance from the butt-end. The [110] single crystal has regions of higher density near the butt-end. Different patterns of shear on the side faces of [