Physico-mechanical properties of modified antifriction coatings based on babbitt B83
¹Operation and repair of machines, Izhevsk State Agricultural Academy, Studencheskaya steet 9, Izhevsk, Russia
²Technologies and equipment for food and processing industries, Izhevsk State Agricultural Academy, Studencheskaya steet 9, Izhevsk, Russia
³Theoretical mechanics and materials resistance, Izhevsk State Agricultural Academy, Studencheskaya steet 9, Izhevsk, Russia
⁴Ural State Agrarian University, Street Karla Libknekhta, 42, Ekaterinburg, Russia
The introduction presents the primary reasons for the decrease in the working efficiency of plain bearing assemblies and suggests key areas for the formation of a stable working capacity of these assemblies.
In addition, the introduction discusses preexisting methods for improving the working efficiency of plain bearings. These methods are based on the use of antifriction coatings and have the drawbacks which are considered in the text. The authors proposed a technology for producing an antifriction coating based on a metal composition. This antifriction coating is produces by high-speed laser processing of powder materials. The technology allows to create antifriction coatings, which have significant wear resistance and the effect of self-lubrication while also provide a minimum run-in time of the bearing assembly.
The methodology validates the choice of materials for the formation of an antifriction coating. An alloy with significant tribotechnical properties based on babbitt B83 was chosen as the basis (matrix). To improve the bearing capacity of the coating, the babbitt base was transformed with MoS2 molybdenum disulfide. The laser radiation usage in the formation of an antifriction coating based on babbitt B83 synthesizes finely dispersed intermetallide phases and forms a porous coating structure due to incomplete melting of the powder material. Molybdenum disulfide is released mainly through the porous structure, which leads to self-lubrication of the bearing assembly during oil starvation.
The results of microstructural and X-ray diffraction analysis are presented to display the structure of the obtained coatings based on antifriction materials. Research value is characterized by the presence of the following intermetallide phases in the structure of the formed coating: Fe2Sn, SnSb, Cu3Sn. The dispersivity of the formed phases is much greater than that of standard babbitt coatings, which is determined by higher crystallization rates under conditions of laser radiation processing. The analysis of diffractograms makes it possible to conclude that the distribution of intermetallide phases along the coating depth is uneven. The underlying layers close to the basis (matrix) are more soft and supple due to the presence of α – solid solution. The surface layers are solid and saturated with the finely crystalline Cu3Sn phase. The research undertaken on formed
coating under conditions of dry friction allows to conclude that the antifriction coating can work without supplying lubricant to the bearing assembly.