Test Type: Forensic and Failure Analysis

Case Study: Degradation of Al Coating on an Optical Component

Deterioration in the performance of a high precision optical component used in a space telescope led to investigation of the aluminum thin film deposited on its surface.  Using AES and ion sputtering, the depth profiles of Al⁺ and O^- in the aluminum coating were obtained.  The results illustrate that the aluminum thin film has multiple internal oxidation layers.  Therefore the failure of the optical component was linked to inconsistent vacuum levels during deposition process.