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