Accession Number:

AD0260794

Title:

THE INVESTIGATION OF THE MECHANISM OF SUBSTRUCTURAL FORMATION IN REFRACTORY METALS AND THE RELATION TO THE OBSERVED MECHANICAL PROPERTIES

Descriptive Note:

Corporate Author:

MATERIALS RESEARCH CORP YONKERS N Y

Personal Author(s):

Report Date:

1960-12-01

Pagination or Media Count:

1.0

Abstract:

An apparatus is described for preparing 9-in.long Mo crystals by floating-zone electronbombardment melting. An assessment was made of the effects of a q ality of starting material, b speed of growth, and c molten zone size on crystal perfection and purity. Three etchpit techniques for revealing dislocations and sub-boundaries in , Electron bombardment, Microstructure, Solid state physics, Refractory materials, Lattices, Deformation. An apparatus is described for preparing 9-in.long Mo crystals by floating-zone electronbombardment melting. An assessment was made of the effects of a q ality of starting material, b speed of growth, and c molten zone size on crystal perfection and purity. Three etchpit techniques for revealing dislocations and sub-boundaries in Mo a chemical etching in potassium ferricyanide-sodium hydroxide, b electro-etching in sodium hydroxide, and c electro-etching in oxalic acid, have been investigated. All of the technique appear to give the same sub-boundary configurations, but etching treatments c produces more random etch-pits than the treatments a and b. Comparative creep tests were made at 1000 C on asgrown and polygonized beam-melted Mo crystals. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE