Electrodeposition of tungsten coatings on titanium from tungstenpyrosulphate melts 

Uskova N.N.,
 
Shakhnin D.B.,
 
I.Gab,
 
Malyshev V.V.,
 
Bing Lee
 

I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Omeliana Pritsaka str.,3, Kyiv, 03142, Ukraine
Adhesion of Melts and Brazing of Materials - Kiev: Frantsevich Institute for Problems of Materials Science NASU, 2016, #49
http://www.materials.kiev.ua/article/2334

Abstract

The possibility of increasing the corrosion resistance of titanium by applying tungsten electroplating from melts is considered. The electrochemical behavior of tungstate-pyrosulphate melts has been studied by potentiometry, voltammetry, potentio- and galvanostatic electrolysis. It is shown that manyelectron equilibria and processes involving di-tungstate ions can be realized in the melt Na2WO4—Na 2S2O7. The galvanic coating with tungsten titanium transforms titanium into a passive state and reduces the rate of its corrosion in H2SO4 (9,5 ppm) at 70—80 °C in 2000—4000 times. The anod ic and cathodic behavior of titanium-coated samples with tungsten is determined by the electrochemical properties of tungsten. The efficiency of the cathodic process on the coating is higher than on the tungsten itself, which makes it possible to transfer the titanium into a passive state and provide electrochemical protection.


COATINGS, CORROSION, ELECTROLYSIS, MELT, TUNGSTEN