With tendency towards new technologies and comfort, we often cross-paths with
different materials and their unique mechanical properties and corrosion stability. And
while reducing costs is commendable, there are cases where cost reductions happen
at the expense of long-term solution. As a result, we often witness corrosion induced
defects and material failure. Corrosion is a spontaneous process, where metal
transforms back to thermodynamically efficient state, which is usually in a form of
oxides. The rate of corrosion process is a direct result of environment and corrosion
media, as well as electrochemical potential of given metal. Even the presence of
humidity in atmosphere is considered as a corrosion medium for metals.
Although corrosion process is inevitable to some degree, we can still slow down the
progression or, in some cases, stop it completely. In order to do so, we can use many
different corrosion protection approaches, such as organic and inorganic protection
layers, layer of less or more reactive metals, by imposing potential onto metal or
adding corrosion inhibitors in a surrounding medium, i. e., electrolyte. While most of
metals and alloys are susceptible to material failure due to corrosion, some form a
passive surface layer and patinas that serves as a protection against further damage.
Since corrosion tests require long-term exposure to elements, we often conduct
preliminary laboratory tests. These tests can be considered as simulations and help
to determine the course and setup of subsequent testing in actual environment.
Therefore, it is faster and more efficient if the corrosion tests are previously carried
out in a laboratory environment with electrochemical tests in an aggressive medium
such as sodium chloride solution. By comparing different electrochemical tests, we
can assess which materials meet the prerequisites for a specific application and,
based on these, decide on the most suitable tests in a real environment.
This thesis deals with electrochemical studies on copper samples and copper-nickel,
copper-nickel-zinc and copper-nickel-zinc copper alloys, which are indispensable
materials in a wide range of applications. The effects of different pH values of the
sodium chloride solution on the corrosion resistance of these materials were
investigated. As a method of corrosion protection, the addition of the organic inhibitor
2-mercaptobenzimidazole was tested, which proved to be effective not only for
copper but also for copper alloys. Copper and copper alloys typically to form a patina
in the air over time. The performance of the corrosion inhibitor was therefore also
tested on surfaces modified with two different types of patina.
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