Machinery & Energetics

The article deals with the issues of increasing the wear resistance of working bodies of agricultural machines. It is noted that in case of insignificant workout some working bodies of machines lose their working capacity as they are exposed to the abrasive particles. The prospects of using composite ceramic-metal materials as wear-resistant coatings on soil-forming elements of working bodies of soil-tilling and seeding machines have been analyzed. The hardness of the matrix and the required difference in the microhardness of the reinforcing and coupling phases are indicated. Preconditions for conducting theoretical research have been formed. On the basis of theoretical analysis, the values of normal and tangential stresses acting on the particles of ceramic filler at fast and slow cooling are determined and conditions for preventing their destruction are determined. The size of the ceramic filler and its volume content in the composite coating are substantiated, taking into account coefficients of thermal expansion of the matrix and ceramic filler, and the differences of heating and cooling temperatures. It was established that the wear resistance of the obtained coating is characterized not only by the composition, metal matrix and the size of the ceramic filler, but also its volumetric content in the composite coating. By solving analytical expressions, a graphical three-dimensional dependence is provided that allows the formation of the volumetric content of the ceramic filler, depending on the ratio of the size of its particles and the size of the abrasive particles of the soil. Using the results of this study will increase the resource of working machines of agricultural machines working in the soil environment and gain a positive economic effect in real economy.

soil medium, composite material, composition coating, metal matrix, ceramic filler