Failure of Rubber Seals
Rubber seals intended for use as door seals were appearing to "bubble". The bubbling problem had stopped production. Closer inspection of the bubbles by Imaging Secondary Ion Mass Spectrometry showed the particulate to be sodium carbonate (shown in red against the green rubber substrate). The contamination was traced back to a process contaminant in early stage production, it was removed and production restarted.
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Failure of Electronic Components
A polyester based foil was showing poor seal strengths when bonded to a gold finger region of a printed circuit board. The bonds were investigated using Secondary Ion Mass Spectrometry and poly(dimethyl siloxane), PDMS, was found. Analysis of the foil and the printed circuit board revealed that PDMS was present on the printed circuit board. PDMS is a notorious culprit in causing delamination. A cleaning method was developed by CSMA to remove PDMS before the foil is bonded to the board resulting in an increase in the bond strength.
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Automotive Glass
Circular defects were observed on the surface of coated glass, utilised in the automotive industry, after a long period of storage. Optical Microscopy showed the size of the defects and the presence of a particulate at the centre of each defect. Further investigation by Depth Profiling SIMS of defective and non-defective areas showed the layer composition of the coated glass and the presence of a silicon-rich particulate in the defect region. It was determined that localised stress caused by the particulate was responsible for the visual distortion.
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Sticking Valves
Valves, which are used in a power steering assembly, were sticking causing the steering to fail. The valves were examined by CSMA and a metallic deposit was found. Topographical measurements showed that the height of the deposit was above the tolerance range of the valve. The debris was identified as corrosion product and it was concluded that hot weather resulted in non-cylindrical symmetry of the valve which resulted in wear and debris. Results from CSMA's investigation lead to improved machining techniques that eliminated debris.
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