First, characteristics
Alumseal W-2000 is a cyanide-containing zinc sinker that produces a dense and uniform thin layer of heavy zinc on the surface of aluminum alloys, providing a good combination of direct copper plating, nickel plating, and chemical nickel deposition for subsequent processes. Particularly suitable for aluminum alloy wheel shell plating.
Second, the bath composition and operating conditions
Raw materials and operating conditions
Standard range
Pure water
400-450 ml/l
Alumseal W-2000
550-600 ml/l
temperature
16-30°C
time
20 seconds - 2 minutes
PH
12.8-13.6
Third, solution maintenance
1. Low-volume applications can be supplemented with Alumseal W-2000, and for every 1.0 g/L of sodium hydroxide added, 6 mL/L of Alumseal W-2000 can be added.
Without adding, 1 liter of solution can handle 2.46 square meters of workpiece (immersion time is two minutes).
2. Alumseal W Replenisher C and Alumseal W Replenisher B can be used to replenish metal components and adjust alkalinity, respectively, in high-volume applications (eg, aluminum shell plating).
Fourth, supplementary methods
1. Add according to the specific gravity of the solution
For each increment of 0.01 unit, 12% (by volume) of Alumseal W-2000 can be added. Alternatively, 2.5% (by volume) Alumsea W Replenisher B and 2.4% (by volume) Alumseal W Replenisher C can be used instead.
SG
°Be
1.180
22.0
1.175
21.4
1.170
20.9
1.165
20.3
1.160
19.8
1.155
19.3
1.150
18.8
1.145
18.3
1.140
17.7
1.135
17.1
1.130
16.5
1.125
16.0
1.120
15.4
1.115
14.9
1.110
14.2
2. Add Alumseal w-2000 Replenisher C by Titre Value according to the analysis result:
For every 0.1 titration increase, add 1.5 ml/l of Alumseal W Replenisher C.
Add Alumseal W Replenisher B at Sodium Hydroxide Concentration:
For every 1.0 g/L increase in sodium hydroxide concentration, 2 mL/L of Alumseal W Replenisher B can be added.
V. Precautions
1. Alumseal W Replenisher B is a concentrated solution of strong alkali, which needs to be added in a small amount with stirring for a few times to avoid local overheating of the working solution.
2. The working fluid contains cyanide. Be careful to avoid mixing with acid and create a hazard.
3. Do not add a large amount of additives during production, and add them in small amounts to make the working solution mix evenly and avoid roughening the surface of the workpiece.
Sixth, analysis method
1. Determination of Titre Value: - Take 2.0 ml of test solution. - Add 5.25% sodium chlorate solution, stir and let stand for 10-15 minutes. - Add purified water to 100 ml. - Add 1-2 grams of sodium bisulfite, stir and let stand for 10-15 minutes. - Add 10 ml concentrated ammonia to the solution light blue. - Add ammonium nitrate indicator. - Use 0.1M EDTA standard droplets to dark purple as the end point.
The titration titer of EDTA is Titre Value.
2, Determination of sodium hydroxide concentration:
- Take 5 ml of test solution. - Add 20 ml of 1N hydrochloric acid. - Add 100 ml of pure water. - Add 3 drops of methyl orange indicator. - Use 1N sodium hydroxide standard drop until pink to yellow.
Calculation: NaOH (grams/liter) = (20-1N NaOH milliliters) x 8
Note: The above analysis method has toxic gases in the test process. Please test in the exhaust cabinet.
To ensure safety.