About Corrosion

How to prevent corrosion?

What is phosphatization?

Iron Phosphate and its Applications

Zinc Phosphate and its Applications

Why is Passivation used?

Manganese Phosphate and its Applications

Aluminium Chromate and its Applications



Aluminium Chromate and its Applications

Before paint, the surface can be prepared with three different methods which are developed for aluminium and aluminium alloys in terms of surface treatment applications.

1- Aluminium acidic degreasing – Rinsing two times – Chromate – Rinsing
2- Aluminium acidic degreasing – Rinsing – Nitric acid bath – Rinsing – Chromate – Rinsing
3- Aluminium alkaline degreasing – Rinsing – Caustic bath – Rinsing – Nitric acid – Rinsing – Chromate – Rinsing

 It is possible to coat the aluminium based materials with yellow, green and transparent coloured chromate. Yellow chromate coats Cr+6, green and transparent chromates coats Cr+3. Coating weight can vary between 0,4-1,5 gr/m² according to application time and coating type. Drying temperature is recommended to be at 60º-80ºC for yellow chromate and 85º-90ºC for green and transparent chromate coatings. Coating is not wanted to be burnt while drying. Heating is used in alkaline degreasing and caustic baths for aluminium alkaline degreasing process. All other baths work at room temperature. Using the special additives developed for nitric acid and caustic baths increases the surface quality. It removes the problems related to the aluminium solution.