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621.762A study has been made on the adhesion of the new composite ceramic AlN − Ti(Zr)B 2 − Ti(Zr)Si 2 with steel 45 and alloy AL9 in relation to the mass-transfer kinetics in spark working. There is a three-stage mass-transfer mechanism. The materials in the electrode and the substrate affect the electrical erosion of the electrode.A feature of coating by spark alloying (SA) is the mass transfer of the erosion products from the anode to the cathode, which determines the thickness and continuity of the alloyed layer, and also the process throughput. Various factors influence the mass-transfer coefficient K t which is equal to the ratio of the cathode mass increment ∆c to the anode erosion ∆a for a specific processing time t (K t = ∆c/∆a). In SA, there is the most active physicochemical interaction between the electroerosion products from the electrode with the substrate material in the liquid formed at the surface. Together with electrode erosion, the mass transfer kinetics are affected by the wetting and adhesion of the components in the coating-substrate system. In SA, a secondary structure with an altered composition is formed at the working surface of the alloying electrode [1] because of compaction of the surface layer and reverse transfer of cathode material to the anode. Therefore, the electroerosion of the secondary structure as the true object of erosion should be dependent under otherwise equal conditions on the substrate material. No research has been done on the effects of wetting and the substrate material on the mass-transfer coefficient.We examined the adhesion between components in the coating-substrate system as affecting the mass-transfer kinetics in SA for AL9 alloy (by comparison with steel 45 and alloy VT6) with the use of composite ceramic electrode materials from a new generation (without metal binding agent) in the AlN − Ti(Zr)B 2 − Ti(Zr)Si 2 system, which provide effective protection from wear and corrosion [2,3].The spark alloying was provided with an Elitron-21 apparatus under the following conditions: short-circuit current 0.9 A, pulse repetition frequency 1200 Hz, and pulse energy 0.08 J. The adhesion was examined under vacuum at 1200°C by the sessile drop method followed by analysis of the composition and structure of the phases formed in the contact zone [4].We examined the mass-transfer kinetics by a gravimetric method [5] by the use of a VLA-200-M balance with an error of down to 0.0002 g, and we determined the specific erosion of the anode ∆a and the specific mass gain in the cathode ∆c for each minute of treatment of 1 cm 2 of surface with allowance for the density of the material. These values

UDC 621:921:661.65The paper examines the mass transfer kinetics, structure, and properties of spark-deposited coatings on magnesium alloys. They are obtained using composite ceramic electrodes in the AlN-Zr(Ti)B 2 and B 6 Si-CaB 6 systems. It is revealed that the microhardness and corrosion resistance of the coatings increase in a 3% NaCl solution and the abrasive wear decreases as compared with uncoated magnesium alloy.