Problem: Discolouration on the surface of premium aluminium cladding was occurring when the building product was installed onsite at a particular location. The client, a building materials manufacturer, was interested to know the identity and cause of this discolouration.
Solution: X-ray photoelectron spectroscopy in the AMMRF at the University of South Australia was used to collect surface-specific information from ‘good’ and ‘stained’ areas of the product. Survey spectra provided the identity and quantity of all chemical species present, and high-resolution spectra of aluminium provided information about its oxidation state. It was found that an etchant in the local environment was responsible for the removal of a protective aluminium-oxide layer, giving the stained appearance.