Etchant
Etchants are acids or chemicals that wet metal samples to make their microstructure visible. Depending on their composition, they react at different rates with different metals and phases.
Physico-chemical mechanism of action
Etchants are chemical solutions specifically designed to wet metal samples and make their microstructure visible. These acids react with the metals at the atomic level, dissolving certain elements from the crystal lattice. This process causes grain boundaries and phases in the metal to become visible.
Metallurgical relevance & welding risks
Correct selection and application of etchants is crucial for a clear analysis of the microstructure. Incorrect or incomplete etching can lead to inaccurate results, which in turn can affect quality assurance in welding. Additionally, some etchants can be toxic and pose health risks if misused.
Workshop practice & action instructions
When using etchants, it is important to use the correct concentration and proper time interval. Always read the safety data sheets (SDS) carefully and wear appropriate protective clothing. Use a closed workspace or a proper etching setup to minimize the risk of air contamination. After etching, samples should be thoroughly washed and dried before examination.