Morphology of Gold and Copper Ion-Plated Coatings
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CEN TER
Pagination or Media Count:
Copper and gold films 0. 2 to 2 micron thick were ion plated onto polished 304-stainless-steel, glass, and mica surfaces. These coatings were examined by SEM for defects in their morphological growth. Three types of defects were distinguished nodular growth, abnormal or runaway growth, and spits. The cause for each type of defect was investigated. Nodular growth is due to inherent substrate microdefects, abnormal or runaway growth is due to external surface inclusions, and spits are due to nonuniform evaporation ejection of droplets. All these defects induce stresses and produce porosity in the coatings and thus weaken their mechanical properties. During surface rubbing, large nodules are pulled out, leaving vacancies in the coatings.
- Coatings, Colorants and Finishes