| Abstrakt: |
The results of the study of the phase composition and corrosion resistance of plasma coatings from composite powders based on intermetallic in tial with the introduction of non-metallic refractory compounds (siC or si3n4) into its composition are presented. the plasma coatings were deposited on the specimens of st3, amg3 and vt6 alloys. the coatings were studied by the methods of metallographic and X-ray structural phase analysis. the studies of electrochemical properties of the plasma coatings were carried out by the potentiostatic method in a 3 % NaCl solution. As initial materials for plasma spraying, the composite powders TiAl-SiC, TiAl-Si3n4, produced by the method of mechanochemical synthesis were used. using the method of X-ray structural analysis, it was revealed that the phase composition of the plasma coatings for TiAl-SiC system consists of the following phases: tial, tial3, tiC, ti5si3, ti3alC, tiO2, and for the coating TiAl-Si3n4 from the phases ti2al, ti5si3, tin, tiO. the average thickness of the coatings was 200 ± 50 µm and the porosity did not exceed 10 %. It was found that the introduction of siC or si3n4 into the composition of the composite coating leads to a decrease in the corrosion current in a 3 % NaCl solution by about an order of value, and the corrosion resistance of St3, AMg3 and VT6 alloys increases by 12-13, 8-9, and 1.8-2.0 times, respectively. The service life of the plasma coatings made of TiAl composite powders with the addition of siC and si3n4 was calculated. The studied coatings belong to the class of resistant and are capable to protect metals in a 3 % naCl solution for a period from 6 to 10 years. [ABSTRACT FROM AUTHOR] |
