Four typical analyses are summarized below as examples of what we can provide.
- Oxidation and Corrosion
- Failure Analysis
- Life Assessment of a Diffusion Coating
- Thermal Spray Optimization
Oxidation and Corrosion Evaluations
Components operating at high temperature are always subject to oxidation attack. When the operating environment also includes contaminants such as sodium (Na) and sulfur (S), hot corrosion may compromise component life at an even greater rate. A typical example of oxidation attack is shown here. Our analytical capability will allow us to identify the mode of attack, estimate the rate of attack, and, if hot corrosion is involved, identify the nature of any contaminants that may be the cause.
Failure Analysis
A failed weld in a machined area, as an example, may be examined by optical microscopy and scanning electron microscopy at various magnifications. Contrasting the microstructures and composition gradients in failed and unfailed areas, as well as comparing the relative amount of metallic and non-metallic phases present in those areas, can give us a clue as to the cause of the failure. Knowing the cause will help us recommend ways to prevent recurrence of the failure.
Coating Life Assessment
High temperature coatings are used to protect turbine hot section components from oxidation and corrosion attack. Evaluation of the changes in the metallurgical structure of these coatings as a function of operating time, such as shown in this picture for a serviced MCrAlY coating, allows an estimate of remaining coating life to be made. Techniques have been developed which enable this assessment to be made for both MCrAlY overlay and diffusion aluminide coatings.
Thermal Spray Optimization
A comparative investigation can be managed to optimize final microstructure, properties and deposition efficiency. This can be achieved by tuning gas flow paramaters, gun voltage and current, and particle size distribution. This type of report will demonstrate how a Design of Experiments can be utilized to optimize coating microstructure by progressive, logical parameter variations.
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