CHARACTERIZATION OF ANODIC OXIDE COATINGS ON ALUMINUM BY TRIBOSTIMULATED EXOEMISSION

It has been well established that during the tensile elongation of metals coated with anodic oxide films, negatively charged particles are emitted from the oxide, an effect referred to as tribostimulated exoemission. We have measured this emission from a variety of oxide layers on aluminum clad A1 2024 and established emperical relations between the characteristic exoemission curve (CEC) and the oxide properties. Changes in the oxide due to variation of key parameters during anodization, oxide age (time between anodization and testing), and sealing time (time immersed in boiling water following anodization) all resulted in noticeable changes in the CEC. Our data indicate that the CEC of an oxide-substrate system could serve as a sensitive indicator of deviations from a desired oxide layer. © 1979.