ELECTROEROSION BEHAVIOR OF A CERAMIC BASED ON BORON CARBIDE: PHASE COMPOSITION, STRUCTURE, AND PROPERTIES OF PROTECTIVE SPARK COATINGS

摘要

Measurements have been made on the erosion resistance of B_4C - 15 percent TiB_2 materials made by reactive sintering on hot pressing of B_4C - TiO_2 - C powder mixtures. The composite material is used as an electrode for treating steel and titanium surfaces in spark alloying. It is shown that the method of preparing the boron carbide influences the erosion resistance of the ceramic much less than it does for the mechanical properties. The surface layers of the electrode materials are affected by the electrical discharge and give rise to secondary structures because of chemical interaction between the electrode materials on the one hand and elements in the gas medium on the other. The properties of these structures are responsible for the erosion characteristics of the electrode material and for the compositions and qualitative properties of the coatings.