Thermal and Diffusion Processes during Electron Beam Processing of Surfaces of Electroexplosive Alloying

The mechanisms of hardening surface layers of carbon steel 45 after combined treatment including electroexplosive boroaluminizing, aluminizing with silicon carbide, and electron beam processing (EBP) are revealed. The combined processing leads to an increase in the hardening depth. After the electroexplosive boroaluminizing and EBP, the microhardeness is 16 GPa and the hardening depth is 90 μm; after the electroexplosive aluminizing combined with silicon carbide and EBP, the microhardness is 12.5 GPa and the hardening depth is 50 μm. In the initial state, the microhardness is 2 GPa. In the conditions of dry sliding friction, the wear resistance increases by a factor of 43 after electroexplosive boroaluminizing and EBP, and by a factor of 12 after electroexplosive aluminizing with silicon carbide. The surface hardening is achieved as a result of the formation of fine-disperse nonequilibrium structure containing strengthening phases. The models developed in this work allow one to explain the results by the peculiarities of the thermal and diffusion processes during EBP.