Anodic spark coatings on titanium and AMuM alloy from baths containing aluminum polyphosphate complexes

The effect of the concentration of aluminum oxalate in an aqueous electrolyte containing sodium hexametaphosphate on the elemental and phase composition of the resulting coatings was studied with the use of (27)AI NMR spectroscopy, x-ray diffraction, and x-ray spectral analysis. With an increase in the concentration of Al2C6O12 . nH(2)O, the content of aluminum in surface films grows on titanium and descends on the aluminum alloy. The coatings become enriched with the crystalline AlPO4 phase. The results obtained confirm that the components of an electrolyte penetrate into anodic layers via high-temperature thermolysis of hydrated aluminum polyphosphates in the near-channel zone of electrical breakdowns.