Aluminium phosphate coating

1)form a stable inert coating on the metal 2)provide excellent paint adhesion 3)inhibit the spread of corrosion from damage

Aluminium phosphate coating agent

1. Overall

IC-AZ aluminum phosphate coating is a new product that aims at poor paint adhesion for aluminium piece and aluminium alloy. It provides excellent paint adhesion and inhibits the spread of corrosion from damaged area. It has the merits of stable performance and strong processing ability. The aluminium phosphate coating agent is suitable for the large-scale assembly line by  spraying ,dipping or  the combining of spraying and dipping.

2. Process flow

   degreasing→ rinsing→ rinsing → delustering → rinsing → rinsing → phosphating → rinsing → rinsing → drying → painting

3. Technical indictors

Phosphating temperature(°C)	30~36	Phosphating film appearance	Even and intact film From colorless to light blue
Treatment time(min)	5~10	Phosphating film thickness	3~4µm
Total acidity of Concentrated fluid	1035~1085	Adhesion of paint	One grade
Specific gravity	1.41±0.01	Treatment mode	Spray ,dip
Total acidity of working solution	19~24

4.  Usage

4.1 Medicament: IC-AZ

4.2  Preparation(calculated by 1 ton):

Weight ratio: IC-AZ: water=1:4

First add water to tank by 50-60 percent; Then add 200KG IC-AZ and stir evenly.

4.3 Tank parameter

                      Dipping                   Spraying

  Total :            19~24                      19-24

Temperature :      30~36°C                   30-36°C

Time :             5-10min                    3-5min

Pressure:           ------------                   0.8-1Kg/cm2

4.4  Supplement and adjustment of tank solution (calculated by I ton)

Because tank solution is used continuously,the active ingredient decreases. Add IC-AZ to tank solution when total acidity less than 19, total acidity can increase one point after add 10.6KG original solution at one time.

5.  Examination and analysis               

5.1 Total acidity of working solution

  Take 10ml working solution to volumetric flask, constant volume 100ml, then take 10ml diluents to conical flask, add 3-4 drops phenolphthalein indictor, titrate with 0.1M NaOH till yellow to saffron yellow, the quantity of 0.1M NaOH consumed is the total acidity.

5.2  The content of chromium ion (Cr6+) in working solution:

Take 5ml working solution to conical flask, dilute with 50ml distilled water, add 20ml 25 percent H2SO4,2-3g KI and 1-2ml 11 percent starch solution, then titrate with 0.1M Na2S2O3 .When the solution turns from red brown to dark green, the ml quantity of 0.1M Na2S2O3 consumed is the point of Cr6+.

6.  Notes

6.1 Degrease thoroughly, water rinsing must be completely after degreasing ,furthermore there is no water remaining on the surface of workpiece.

6.2 Delustering thoroughly, or it will be ashy on the surface of workpiece after phosphating.

6.3 The phosphate workpiece should be dried under 50-60°C,which can improve anticorrosion, but not dry in normal temperature.

6.4  If the phosphating doesn’t do well,  it can be delustered again  and then phosphating!

Aluminium phosphate coating