Formation of Hardening Coatings for Working Elements of Agricultural Machines When Combining the High-Frequency Heating and High-Temperature Synthesis of the Materials

Resumo

A method of surfacing of a wide range of cast, hard, wear-resistant materials on a steel base was created based on the performed investigations. The surfacing was carried out in the conditions of heating with high-frequency currents (HFCs). The exothermic thermite mixtures were used, including the mixtures of metal oxides, aluminum, or silicon. In the course of synthesis, the coatings with the weld pad of 100–900 μm were obtained. The surfacing process was carried out in two main synthesis modes—high and low-temperature using the exothermic thermite mixtures—and allowed extending significantly the raw material base of the surfacing materials, including refusing the use of the traditional surfacing eutectic alloys and charge mixtures with the boron carbide for deep borating. It is shown that the synthesis of the coating of the exothermic thermite mixture FeO/B₂O₃/Si is identical to the diffusion saturation of the surface layer with the classical mode of borating during the HFC-heating.