The structural features of the porous type of anodic oxide coating applied to aluminum have been investigated with the electron microscope. These coatings consist of close‐packed cells of oxide, predominately hexagonal in shape, each of which contains a single pore. Pore size is a function of the electrolyte used and is independent of forming voltage. Wall thickness and barrier thickness are primarily a function of forming voltage and are affected to a minor degree by the electrolyte type. Pertinent dimensions of anodic coatings formed in sulfuric acid, oxalic acid, chromic acid, and phosphoric acid electrolytes are presented, and formulas are given for calculating the cell size and pore volume of these coatings.
known and most useful special case 1-'1 = J.i.2, but generally.The attenuation of a surface wave in the plane of the interface progresses at the rate of Imp. From Eq. (3.5) it appears that this rate is intermediate between the loss rates of plane waves propagating in the two media.The general formalism evolved in the paper contains as special cases the quasi-plane surface waves of Zenneck, P=e ipx , and the radial cylindrical wave, P=H 1(1) Cpr).In this paper, surface waves appeared as solutions of Maxwell's equations which by themselves satisfy the proper boundary conditions at the interface. Therefore, in this formulation their existence is not tied to the presence of waves of other types. Once they are excited by a source they propagate along the interface unaffected by other waves. The questions raised pertaining to their existence in various regions in specific problems, such as the radiation of a dipole, are really questions concerning first the fact of their excitation by the assumed source, and second, the relative magnitude of the fields associated with surface waves when compared to fields of other types present in the region.Frank sessile dislocations surrounding a region of stacking fault are shown to be nucleation sites for ' )" phase precipitation in aluminum-silver alloys. The segregation of silver to these regions is explained in terms of extinction fringe contrast. Direct evidence for "pipe" diffusion along dislocations to a grain boundary is also presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.