I would like to know the pretreatment cycle for depositing platinum up to five microns on titanium mesh. I have tried pickling in HCl and HF/HNO3 but it did not get good bonding. B. R.
Plating on titanium substrates is not easy. The preparation of the titanium substrate requires the use of hydrofluoric acid in combination with other chemicals. Before starting on a project of this type, you must be sure you fully understand the dangers of the materials used in the preparation of the titanium substrate. The following procedure has been used with some success.
2.Clean in hot alkaline cleaner for up to five minutes at 175 – 180F
3.Rinse in DI water
4.Place in a solution of the following for one minute
Sodium dichromate 400 g
Hydrofluoric acid (48%) 25 mL
Water Up to 1 L
5.Rinse in DI water
6.Platinum plate in an ammoniacal plating bath, using periodic reverse current at a current density of 50 ASF. The suggested periodic reverse cycle is: cathodic five seconds, anodic two seconds.