Key Engineering Materials Vol. 910

Abstract: The article presents a technique for experimental studies of microstructure of microsections during rolling of ball pins made of 38KHGNM and 40KH steels. Moreover, photographing was carried out in the pole and equatorial parts of the ball pin head, as well as at the cross-cut end. When analyzing the photographs of microsections, it was concluded that after the final rotary rolling, deformation grinding of the grains occurred in the structure of ball pins.

Abstract: The paper presents methods of obtaining and studying new materials - thin metal films of the Ni/Al system. The technique and main parameters of the resistive method of thermal evaporation of the alloy using a vacuum universal station are briefly presented. Samples of thin films of various thicknesses were obtained. The thickness of the material was determined both using a scanning electron microscope and a developed eddy-current gage system operating under a hardware-software complex. In the course of the research, the limit the film thickness gauging capabilities of the developed gage system was established (400 nm). The ability of the gage system to detect differences in the thickness of the same film was shown using the developed method. Also, the possibility of determining the thickness of an undoubtedly unknown thin film by an eddy-current transducer signal amplitude has been demonstrated.

Abstract: In the present work, we studied dislocation amplitude-independent internal friction (AIIF) for segment of edge dislocation. Results obtained were compared with results of the Koehler-Granato-Lücke string model. Expression for dislocation effective rigidity and effective mass, obtained earlier by applying generalized susceptibility of dislocation, is used. Dependences of dislocation effective rigidity on dislocation segment length, dislocation effective mass on frequency and segment length, internal friction on for various values of frequency and segment length are plotted. Case of elastic interaction of the dislocation segment with pinning points is also investigated. It was found that main effect of elastic interaction the dislocation with the pinning points is reduces to influence in the effective rigidity. Plots of internal friction dependence on frequency for various values of distance between the dislocation and the pinning points are constructed.

Abstract: The mechanical properties of steel often determine to a greater extent its performance characteristics, including service life of the equipment. Often, for operational control of mechanical properties, magnetic parameters are used such as, for example, the coercive force. Both mechanical and magnetic properties of steel are associated precisely with the structure of the material. The influence of the structure on these properties became known a long time ago, however, in similar works, the influences exerted by the structure with different degrees of dispersion are not considered. In this work, the goal was set to consider the effect of grain size difference on the magnetic and mechanical characteristics of steel.

Abstract: The disadvantage of reinforced concrete structures is their gradual destruction at high temperatures, above 250-300°C under the influence of fire, due to disturbance of cement binder structure. Therefore, the development of a fire-resistant composition for reinforced concrete is urgent. The article describes the study of tetraethoxysilane (TES) 6% and 10% as a fire retardant additive for sand-cement mortar, for building structures made of metal, the experimental study of sand-cement mortar using tetraethoxysilane 6% and 10%, with different methods of application to the metal is stated. An assessment of the effectiveness of TPP in interaction with sand-cement mortar is given.

Abstract: The article presents comparative data on the properties of different materials used for the manufacture of bearings. The influence of the chemical composition and structure of titanium-based alloys on the change in hardness during various types of processing is studied. It is shown that the most promising for the manufacture of bearings are high-alloyed titanium alloys of the VT22 type, in which the hardening heat treatment allows to obtain a high hardness.

Abstract: Work on the current topic of hybrid titanium-polymer composite materials (TPCM) is continuing. After checking the technological feasibility of two-stage processes for manufacturing parts of flat shapes and with a single curvature, identifying opportunities for improving the adhesive interaction, work is carried out to assess the possibility of varying design parameters, such as reinforcement schemes, combinations of components, etc.in order to obtain optimal properties of manufactured parts.

Abstract: The results of experimental modeling of the wear characteristics of medical materials during friction with high molecular weight polyethylene under conditions close to the operation of a tribological pair of a hip joint prosthesis are presented.

Abstract: The paper considers phase transformations in the E110 zirconium alloy with multilayer CrN/Cr coatings under linear heating up to 1250 °C with isothermal exposure for 20 min. The multilayer CrN/Cr coatings can decelerate Cr-Zr interdiffusion by formation of a barrier ZrN layer at the “coating-alloy interface” due to CrN decomposition at high temperature. The duration of barrier effect depends on a layer thickness of CrN/Cr multilayers. This effect results in a better corrosion resistance of the E110 alloy with multilayer CrN/Cr coatings under high-temperature oxidation at 1100 °C in air in comparison with Cr-coated E110 alloy.

Abstract: A comparison was made of the properties of porous coatings obtained by ion-plasma spraying methods, 3D-coating obtained by direct laser metal deposition (DLMD), as well as a GRIPTION® and POROCOAT® coating. The influence of various methods of obtaining a porous coating on the porosity and structure of the coating, as well as the effect of thermal hydrogen treatment (THT) on the adhesion strength of the titanium coating was determined.