Coatings Technology

The Coatings Technology Branch of the Mercer Engineering Research Center (MERC) has researched, developed, and tested several systems for applying and removing coatings.

C-130 Blade Life Enhancement Coating

Scientists and engineers at MERC have developed a specialized coating for improving the life expectancy of the C-130 aluminum propeller blades. This coating is a unique combination of two industrialized processes: hard anodize and IVD (ion vapor deposition of aluminum).
This combination was chosen after a study of the requirements that a coating would have to have to meet to enhance the life of the blade and the process requirements demanded by the customer. The driving process requirements were: maximum process temperature of 190° F, not affect the base material’s mechanical properties (fatigue, tensile, etc.), and the process should already be industrialized. The coating system needed to be harder than silca, since it was determined that the main cause of erosion was from sand impact during landing operations on rough field conditions.
The hard anodize outer layer has Rc 65, which is harder than silica. Unfortunately, hard anodize has a detrimental affect on the substrate to which it is plated. MERC engineers then proposed an intermediate coating of pure aluminum to act as a buffer between the hard top coat of anodize and the 7076T6 substrate material.