Titanium has obscured the glitter of gold30 октября 2013 года
Titanium has obscured the glitter of gold
It is possible to say that pilot products with coloured titanium elements were much more interesting to many people than the glitter of a large number of gold and silver coins at the exhibition. The Research Institute of Goznak presented tokens consisting of the metal core minted into the titanium ring with the help of a special lock.
The idea was developed by the Research Institute in co-operation with the Coin and Order Directorate of Goznak. It was decided to create a set of tokens with the application of metals of different colours. Titanium was chosen as a material – it is quite cheap to compare to other valve metals able to change colour.
The majority of the mints use valve metals as the core of a combined product. It is much easier to do that than to make an outer ring. It is a technologically complicated task to make a ring of titanium, but it has been solved at Goznak. A man apprehends the colour scheme of the outer ring, and perceives the core as an addition.
Titanium changes colour during thermal processing, but this time electrochemical colouring was applied. But in order to achieve purity and intensity of colour, we had to abandon the standard technology and modernize the process. Titanium is hard to process. It is both an inert and active metal because there is a thin film of titanium oxide in it. If the film is removed, titanium becomes a very active material. During the minting process we observed diffused welding of two metals. But Goznak has managed the problem too.