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The two laboratories of the Horn & Co. Group work closely together to solve complex problems.
For over a year now, Tritech Oberflächentechnik GmbH has been part of the Horn & Co. Group. The addition of corrosion testing, metallography, and analytics located there represents an ideal complement to the analytical spectrum of Horn & Co. Analytics GmbH and to the service portfolio of the Horn & Co. Group. Together, we are able to investigate and answer complex issues – for example in the field of failure analysis – in a holistic manner. After successfully completing the first year together, one thing is clear: it was a perfect match.
An interesting and also typical case was recently handled jointly: the cause of water damage was a severely corroded copper pipe (Figure 1). The task was to determine the cause of the corrosion. Initially, the investigation was carried out using optical and microscopic methods. Subsequently, the corrosion residues were analyzed for their elemental composition and the compounds they contained.
The optical and microscopic examination (Figure 2) showed that the pipe was corroded both externally and internally, with the internal attack being significantly more severe. The recorded images clearly showed that the inner, natural protective layer of copper oxide – which normally protects the copper from corrosion – was not fully developed. This allowed deposit corrosion to occur, which, due to its volumetric expansion, further destroyed the protective layer and even lifted it from the copper itself.
Confirmation of the microscopic results was provided by localized elemental analysis using an electron microscope (SEM-EDX, Figure 3) as well as X-ray diffraction (XRD). The elemental analysis showed that the deposits inside the pipe did not consist solely of copper and copper oxide, but also contained other elements such as carbon and sulfur. Using X-ray diffraction, compounds such as copper oxide, basic copper carbonate (malachite), and copper sulfate (brochantite) were identified within the deposits.
Overall, the results lead to the following conclusion: due to the incomplete protective layer of copper oxide inside the pipe, it was possible for deposits from the water flowing through the pipe to form. These deposits further damaged the protective layer and ultimately led to the progression of pitting corrosion, resulting in the failure of the pipe.
If this case sounds familiar to you or if you have other complex issues where you require support, please feel free to contact us. We are happy to assist you in finding a solution. You can reach us at anfrage-analytics@horn-co.de or info@tritech.de.
