Here I have at my work place the passivation process.
It would work for most of the time with new solution but only last for a month or so and parts would start failing and the phosphoric acid would need to be change.
For more complicated parts (bigger and more edges/holes made from NC), it would fail very often even with new solution.
Wondering what would be the problem.
Here is general process
Electro Polish with current through 5 mins
Rinse
Phopsphoric Acid 5 mins
Rinse
Type 2 Passivate 30 mins
Rinse
Dichromate Treatment 30 mins
Rinse
Hot Water Seal 1 mins
Spin Dry
It would work for most of the time with new solution but only last for a month or so and parts would start failing and the phosphoric acid would need to be change.
For more complicated parts (bigger and more edges/holes made from NC), it would fail very often even with new solution.
Wondering what would be the problem.
Here is general process
Electro Polish with current through 5 mins
Rinse
Phopsphoric Acid 5 mins
Rinse
Type 2 Passivate 30 mins
Rinse
Dichromate Treatment 30 mins
Rinse
Hot Water Seal 1 mins
Spin Dry