International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

X-Rays diffraction method were used to determine the residual stresses and local phase composition through the thickness of as-sprayed by flame-sprayed thermal barrier coatings consisting of a NiAl bond coat and composite ceramic coatings (Al2O3 –22wt% ZrSiO4) topcoat produced. The as-sprayed residual stresses reflected the combined influence of quenching stresses from the flame spray process, thermal expansion mismatch between the topcoat, bond coat and substrate, and stress relief from the segmentation cracks. The thickness of bond coating was (150ϻm) and for composite ceramic coating was (450 ϻm). The residual stresses evaluated by X-Ray diffraction technique were maximum tensile residual stresses (15.626) Mpa.

The effect of the low-frequency vibration processing on the residual elastic stresses in the Ti-6Al-4V alloy manufactured by 3D printing (Selective laser melting) was investigated. The studied sample was manufactured horizontally in respect to the building platform. Different vibration oscillations modes (vertical, horizontal, and elliptical) were chosen for study. The oscillations were done with frequency of 16 Hz, and a processing time was 20 minutes. Studies shown that 3D printed sample had a high level of residual elastic stresses, which were changed after vibration treatment. The optimal parameters of vibration processing, which provide a minimum level of residual elastic stresses in 3D printed Ti-6Al-4V alloy are discussed.

The present article examines the technical and economic advantages of vibratory stress relief from the restored steam turbine blades. It is presented the background technology of the offered vibration method of the structure stabilization of weld metal that im-proves the operational reliability of turbine blades.

X-ray diffraction analysis studies the formation of a stress-strain state of single-crystal composites LaB6-TiB2 obtained under identical conditions by crucible-free float zone melting (FZM). The composites were obtained using monocrystalline LaB6 substrate seeds with <100>, <110> and <111> orientations. It is shown that indentation-induced deformation in the composite materials obtained by FZM is distinct from the deformation expected in their equilibrium state. This difference arises in part from residual thermal strains in both phases of the composites in a FZM -grown state. Interplay between residual thermal deformations and external mechanical deformation results in a complex distribution of dilatational strain in the LaB6 matrix and TiB2 fibers and differs in composites of different orientations. Reversal sign of the stress-strain state (e.g., alternating tensile/compressive/tensile in central part of the cross-section area) is observed predominantly in the matrix LAB6 and the TiB2 fibers of the composite with the orientation <111>. In the composite with the orientation <100>, this change in the deformation sign was not observed. The size and spread of cracks after indentation-induced deformation shows a decrease in microhardness in FZM -grown composites of <111> significantly more (40%) than in composites with a orientation of <100> (10%) compared with an equilibrium state.

The results of studies of the influence of the type of machining and tool material to the structural state of the surface layer and the fatigue strength of ХВСГsteel during machining are shown. Processing with the composite-10 tool in a surface layer for α – and γ – phases is accompanied only by compressing residual pressure while abrasive processing promotes occurrence of stretching pressure of an I-type. Increasing of cutting speed of the composite-10 tool from 50 to 200 m/min does not lead to significant changes in fatigue strength.