What liquid is used for etching?

The liquid used for etching depends on the specific material being etched and the desired etching process. Different liquids, often referred to as etchants, are used for different materials. Here are some examples:

1. Nitric Acid (HNO3): Nitric acid is commonly used as an etchant for metals such as stainless steel, aluminum, and copper alloys.

2. Hydrochloric Acid (HCl): Hydrochloric acid, also known as muriatic acid, is used as an etchant for metals like steel and iron alloys.

3. Ferric Chloride (FeCl3): Ferric chloride is a popular etchant for copper and copper alloys, including brass and bronze.

4. Ammonium Persulfate ((NH4)2S2O8): Ammonium persulfate is used as an etchant for copper and copper alloys, particularly in printed circuit board (PCB) fabrication.

5. Sulfuric Acid (H2SO4): Sulfuric acid is occasionally used as an etchant, typically in combination with other acids or as part of a multi-step etching process.

These are just a few examples of etchants used for metal etching. The specific etchant used depends on factors such as the material being etched, the desired etching rate and selectivity, safety considerations, and environmental factors.

It's important to handle etchants with proper precautions, adhere to safety guidelines, and consult appropriate resources and experts to ensure the correct selection and safe usage of etchants for a specific etching application.