THE INVESTIGATION OF THE MECHANISM OF SUBSTRUCTURAL FORMATION IN REFRACTORY METALS AND THE RELATION TO THE OBSERVED MECHANICAL PROPERTIES
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1960
- Accession Number
- AD0260794
Entities
People
- A. Iannucci
- M.a. Adams