A surface nanocrystalline steel layer in the low alloy steel 41Cr4 was fabricated by using mechanical-pulse treatment (MPT) with different deformation modes. The structure parameters, the physical and mechanical properties, the wear resistance, and the surface topography parameters of the treated steel depending on the deformation mode were investigated. A tool with a smooth working surface was used for inducing unidirectional deformation in the top surface layer (shear), and a tool with the oppositely directed grooves was used for generating multidirectional deformation. The surface layer with a nanocrystalline structure formed by MPT using both of the tools was characterised by enhanced mechanical properties and wear resistance compared with those of the untreated or heat-treated steels. Inducing multidirectional deformation during the MPT resulted in a decrease in the grain size and an increase in the depth and microhardness of the surface layer due to it facilitating the generation of dislocations compared to those formed under unidirectional deformation. The results also demonstrated that favourable surface topography parameters providing the highest wear resistance of the steel were obtained at MPT using multidirectional deformation.

Vibratory equipment is widely used for performing various finishing processes, machining and forcing of different parts and materials. Numerous researchers and technologists pay specific attention to the possibilities of implementing vibration-driven machinery for conducting the lapping and polishing operations on flat surfaces. The present paper is dedicated to studying the laps kinematic parameters of the vibratory finishing machine actuated by six electromagnets. The paper’s scientific novelty consists in the experimental verification of the previously modelled and simulated circular trajectories of the laps under different operational conditions. The methodology of research contains two basic stages: changing the excitation frequency at the constant traction force and changing the traction force at the constant excitation frequency. The improved 3D-design of the vibratory finishing machine was developed in the SolidWorks software. The experimental prototype was implemented in practice, and full-scale tests were carried out using the WitMotion sensors and software. Based on the obtained experimental data, the trajectories of the machine’s laps were constructed and analyzed in the MathCad software. The research results substantiate the possibilities of providing circular oscillations of the laps at different operational conditions. The results can be used by technologists and engineers while choosing the appropriate design and control parameters for similar vibratory equipment intended for lapping and polishing of flat surfaces.

Thermo-deformation treatment refers to methods of strengthening during which strengthened layers with a nanocrystalline structure are formed in the surface layers by modifying the metal surface layer, which changes its phase and structural and chemical compositions, reduces grain size, and improves performance. Grinding of the metal structure was achieved by combining two methods simultaneously during this treatment: the action of a highly concentrated energy source on the surface layer and intense plastic deformation. The source of highly concentrated energy was generated in the contact zone of the tool-disc, which rotates at high speed during friction on the treated surface. Intense deformation was achieved due to the grooves on the tool’s working surface. Dynamic analysis of the thermo-deformation treatment process of flat surfaces of machine parts and a calculation scheme of the surface grinder machine’s elastic system, which is the three-mass model, were developed. When the groove width increased from 4 mm to 8 mm, the force amplitude in the contact zone increased from 10 N to 75 N. Accordingly, the thickness of the nanocrystalline layer increased from 190–220 μm to 250–260 μm, and its hardness increased from 9.3 GPa to 11.1 GPa.

The paper’s objective is to study the dynamic parameters and operating conditions of the vibratory conveyor, which is based on the double-mass oscillatory system and equipped with the pull-type (single-cycle) electromagnetic exciter. The scientific novelty consists in substantiating the conveying capacity of various standard sizes of bolts at different operating conditions defined by the input parameters, particularly supplied voltage. In order to describe the conveying tray vibrations, the simplified mathematical model of the conveyor’s double-mass oscillatory system is developed using the Euler-Lagrange equations and is numerically solved in the Mathematica software with the help of the Runge-Kutta methods. The experimental investigations are carried out at the Vibroengineering Laboratory of Lviv Polytechnic National University and are focused on testing the conveying speed of various bolts at different motion conditions: detachable (bouncing, hopping, jumping over the conveying surface) and non-detachable (sliding along the conveying surface). The obtained results show the basic kinematic parameters of the conveying tray motion at different voltages supplied to the actuating electromagnet and the dependencies of the conveying speeds of various bolts at different motion conditions mentioned above. The paper may be useful for designers and researchers while improving and implementing similar vibratory equipment in various industries.

During the TDT of 41Cr4 steel specimens, a uniformly reinforced white layer with a nano-crystalline structure is formed in the surface layers. The wear resistance of sliding friction without the lubrication of a pair of steel 41Cr4—grey cast iron EN-GJL-200 (EN) under the face-to-face (“ring-ring”) scheme has been studied. It is revealed that when the sliding velocity changes from 0.25 m/s to 4 m/s and the unit load changes from 0.2 MPa to 1.0 MPa, a pair with a reinforced surface layer on 41Cr4 steel specimens and unreinforced specimens of EN-GJL-200 (EN) grey cast iron has a higher wear resistance than an unreinforced pair. The wear resistance increases for both reinforced and not reinforced specimens operating in a friction pair.