Etching different metals requires different solution formulations and process conditions. For the etching solution formulations and process conditions of commonly used metal materials, see Table 6-4 to Table 6-6.
Table 6-4 Formula and process conditions of metal chemical etching solution
Solution composition and process conditions 1 2 3 4 5
Ferric chloride (FeCl3)/(g/L)
Hydrochloric acid (HCl)/(g/L)
Hydrofluoric acid (HF)/(mL/L)
Phosphoric acid (H3P04)/(g/L)
Copper sulfate (CuS04)/(g/L)
Sulfuric acid (HzS04)/(g/L)
Nitric acid (HN03)/(g/L)
Etching accelerator/(g/L)
Kerosene/(g/L)
Solution temperature/℃
Processing time/min
Applicable materials 800～900
100～120mL/L
80～120
5～8(Leveling agent)
20～50
15～25
Steel 450～560
5～10mL/L
A small amount
20～50
Die steel 600～800
80～120
20～30
80～100
10～45
15～20
Stainless steel 600～650
90～100
8～12
15～50
10～15
Copper alloy 450～550
200～300
10～20
20～40
10～20
Cast aluminum
Table 6-5 Metal copper chemical etching solution formula and process conditions
Solution composition and process conditions 1 2 3 4
Nitric acid (HN03)/(mL/L)
Sulfuric acid (HzS04)/(mL/L)
Chromic anhydride (Cr03)/(g/L)
Sodium chloride (NaCl)/(g/L)
Solution temperature/℃
Etching time/min 1000
20
—
45
20～30
15～20 1000
40～50
60～80
10～15 —
—
50
400
20～30
15～20 50
900～1000
10～20
60～80
10～15
Table 6-6 Chemical etching solution formula and process conditions for zinc castings
Solution composition and process conditions 1 2 3
Nitric acid (HN03, 65%)/(mL/L)
Hydrochloric acid (HCl, 37%)/(9/L)
Solution temperature/C
Processing time 800～1000
20～30
According to the etching depth
210～240
20～30
According to the etching depth
150～300
25～50
According to the etching depth