Metal surface treatment method

[Method 6]

After degreasing, immerse in the following boiling solution for 20 minutes:

Sodium dichromate   1.5  ammonium sulfate 3  ammonia (d=0.88) 0.3   水 93.7

Rinse with warm water, rinse with distilled water, and dry.

[Method 7]

Anodize in 10% ammonium hydride hydride solution below 30°C until the current density is lower than 0.45A/m2 (one electrode panel), AC voltage 90-120V

, Then wash and dry.

[Method 8]

Anodize in the following solution at 20-30°C:

Potassium hydroxide 12  aluminum 0.75  anhydrous potassium fluoride 3.4  sodium phosphate 3.4 potassium permanganate  1.5  water 80

AC voltage 85V, current density 1.1-1.4A/m2, then wash with cold distilled water and dry.

[Method 9]

After degreasing, wash in the following alkaline solution at 70°C for 5-15min:

Sodium hydroxide 23-34    water 400

Wash with cold water for 5 minutes, then immerse in the following solution for 5-15 minutes at a temperature of 55°C:

Chromium oxide 57-68   Calcium nitrate 5  Water 450

Wash with cold water for 2 minutes, then immerse in the following solution for 3-12 minutes at a temperature of 55°C:

Chromium oxide 45  Sodium phosphate 8  Water 450

Wash in cold water for 2 minutes, then dry at 40°C for 30 minutes.

3. Surface treatment methods of copper and copper alloys

[method 1]

Common solvents for degreasing: trichloroethylene, acetone, methyl ethyl ketone, ethyl acetate.

[Method 2]

Degreasing after sandblasting or sanding with emery cloth.

[Method 3]

Dip in the following solution at 25-30°C for 1 min;

Concentrated sulfuric acid   8  Concentrated nitric acid 25  水 17

Then wash with water and dry at 50-60°C.

[Method 4]

Immerse in the following solution at 60-70°C for 10 minutes:

Concentrated sulfuric acid  40  iron sulfate  4.5  水  38

Then wash with water and dry at 60-70°C.

[Method 5]

Soak in the following solution for 10-15min at 25-30°C:

Concentrated sulfuric acid  10  sodium dichromate  5   水 85

Then wash with water and dry at room temperature.

[Method 6]

Immerse in the following solution at 25-30°C for 1-2min:

Ferric chloride   15     concentrated nitric acid   30     water   200

Then wash with water and dry at room temperature.

[Method 7]

After degreasing, etch in the following solution for 10 minutes at a temperature of 66-71°C:

Iron sulfate   4.5     concentrated sulfuric acid   3.4     water   450

Then wash in cold water at 20°C for 5 minutes, and then soak in the following solution:

Sodium dichromate   5  concentrated sulfuric acid  10  水  85

Then wash in cold water, soak in ammonium hydroxide (d=0.85) for 10min, then wash with cold water for 5min

, Rinse with distilled water and dry at 40°C. This method is used for brass and bronze processing.

[Method 8]

Oxidize in the following solution:

Potassium persulfate 1.5  Sodium hydroxide  5  水  100

Immerse for 15-20min at 60-70°C, the surface will be black, wipe it with carbon tetrachloride before bonding. This method is used for copper foil processing.

Four, stainless steel surface treatment method

[method 1]

Common solvents for degreasing: trichloroethylene, acetone, methyl ethyl ketone, benzene, ethyl acetate.

[Method 2]

Degrease after sandblasting or sanding.

[Method 3]

Immerse in the following solution at 70-85°C for 10 minutes:

Sodium silicate   6.4  Sodium pyrophosphate 3.2  Sodium hydroxide  3.2  Descaling powder   1  水  32

After washing with cold water, dry at 93°C.

[Method 4]

After degreasing, immerse in the following solution for 10min, temperature 80°C, PH=12.65:

Sodium phosphate  8.5  sodium pyrophosphate 4.2  sodium hydroxide 4.2  surfactant  1.4  Water  380

Take out the water to wash, and then immerse in the following solution at 65°C for 3 minutes:

Chromium Oxide  20  水  380

Dry after washing with water.

[Method 5]

Immerse in the following solution at 65-70°C for 5-10 minutes:

Hydrochloric acid (37%) 2  hexamethylenetetramine  5  Water  20

Then add 30% hydrogen peroxide, take out the water to wash, and then dry at 93°C.

[Method 6]

Immerse in the following solution at 50°C for 10 minutes:

Potassium dichromate saturated liquid    0.35   sulfuric acid (d=1.84 )  10

Then brush off the carbon residue, rinse with distilled water, and dry at 70°C. This method is suitable for occasions requiring maximum peel strength.