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SHS extruded TiB / 30 wt.% Ti-layered long rods with a length of more than 100 mm and a diameter of 3 mm were made by electric arc surfacing on a titanium substrate in an argon atmosphere. Technological modes of coating deposition (electric arc current, arc speed, argon flow intensity, etc.) have been worked out by the method of electric arc surfacing. The structure and phase composition of the initial surfacing electrode and coating are investigated. It is shown that the deposited coating has a layered structure, its microstructure is represented by titanium diboride and monoboride in a matrix consisting of a solid boron in titanium solution. It was found that the structure and phase composition of the coating are predominantly identical to the structure and phase composition of the used SHS electrodes. The microhardness of the deposited electrode and coating was 1024 and 1420 HV, respectively.

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Due to their unique properties, metal-matrix composite materials, when used as a surfacing material for electric arc surfacing, provide high properties of the deposited layers. SHS-extrusion is a promising method for a wide range of surfacing metal-matrix electrodes. The gas environment of surfacing affects the quality of coatings formed by SHS electrodes, their microstructure and properties. In this paper, cermet SHS electrodes of the TiB2–Co2B composition obtained by SHS-extrusion were used to form protective coatings on a steel substrate by electric arc surfacing in an argon atmosphere and in a nitrogen atmosphere. The elemental and phase composition, as well as the microstructure of the deposited layers, were investigated. Based on the conducted studies, the influence of the gas atmosphere on the formation of the structure of cermet coatings was established. It is shown that, despite the similar phase composition, there are fundamental differences in the microstructures of the deposited coatings, which are caused by the partial fusion of the tungsten electrode and the transfer of the electrode material in the coating during surfacing in an argon atmosphere. The maximum values of the microhardness of coatings deposited in a nitrogen atmosphere exceed the maximum microhardness of coatings obtained by surfacing in an argon atmosphere by 200–450 HV.