The diagram is a schematic of a steel hem structure in which an inner piece is secured to an outer panel by a metal fold or hem. The potential placement of supplemental zinc protection in the vicinity of the hem is illustrated.
Because the duration of galvanic protection by a sacrificial metal such as zinc on steel is linearly proportional to the amount of sacrificial metal available, it then becomes possible to “program” the amount of sacrificial protection according to the severity of the specific geometry and expected service environment.
In this manner, the galvanic protection can be strategically placed instead of relying on large expanses of precoated material to achieve protection goals in localized features. This would be similar in concept to the fabrication of tailored panels of steel with differing strengths and thicknesses for metal forming. Potentially, both weight and cost savings could be realized through such an approach.
Volume 5A, Thermal Spray Technology ⇒ Thermal Spray Processes and Coatings ⇒ Cold Spray Process ⇒ Coating Materials and Applications
