Microstructure Assessment of Copper Materials

Brass, an alloy of copper and zinc, is valued for its good corrosion resistance and workability. It is used in areas where both mechanical stability and a certain resistance to environmental influences are required. Bronze, an alloy of copper and tin (occasionally with other elements such as aluminum or nickel), is also characterized by its corrosion resistance and good mechanical properties and is often used in marine or mechanical applications.

The metallographic examination of copper and its alloys offers a valuable opportunity to assess the microstructure composition and possible impurities. An important aspect is the visualization of copper oxides (Cu₂O) in the microstructure. These oxide inclusions can be made visible under the microscope using special etching processes. Their presence can provide evidence of oxygen contamination in the material, which indicates insufficient degassing or processing of the copper (left image).

In addition, metallographic methods can be used to assess the heat treatment status of copper materials. Changes in the structure that arise from various heat treatment processes such as annealing or hardening can be made visible and evaluated. The structure can also be used to determine the manufacturing method, i.e. whether the component is cast or plastically deformed (right image). Such tests are essential to check the quality of copper components and to ensure that they meet the requirements for corrosion resistance and mechanical properties.