Abstract
Tungsten plating has long been considered difficult and of no practical use. Recently, however, the tungsten plating using fluoride bath enabled the deposited film to have so good metallic luster and to be so thick at any plating temperature of wide range that it has become to be used practically.
The compositions of fluoride plating bath and the plating temperatures are as follows:-
1. For 60g/l of tungsten trioxide, the appropriate amount of potassium fluoride is 30-40g/l. If smaller is the quantity than the above, the deposition is poor and tint color becames black. If larger is thequantity than the above, the deposition is deteriorated having various color.
2. The good result will be obtained by adding sodium hydroxide by 60g/l for to 60g/l of tungsten trioxide. In any case, larger or smaller quantity of the sodium hydroxide than the above is not favourable, and will decrease the deposition.
3. The plating temperature should be higher than 60°C, and the higher the better. In the case of lower temperature, the deposition will not be satisfactory and not hard enough for practical use.
