Accession Number : AD0863815

Title :   The Compatibilities of Boron and Germanium.

Descriptive Note : Technical rept. Aug 68-May 69,

Corporate Author : AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OH

Personal Author(s) : Bidwell, Lawrence R.

Report Date : OCT 1969

Pagination or Media Count : 28

Abstract : The salient features of the boron-germanium phase equilibrium diagram were deduced from X-ray diffraction, metallographic, thermal analysis, and electron microprobe studies on both sintered and melted alloys. The system can be characterized as a classical monotecticeutectic with no intermediate phases. The occurrence of hypomonotectic boron crystals and boron crystals grown from a germanium melt indicates a slight solubility of germanium in solid boron and of boron in liquid germanium at the monotectic temperature. X-ray diffraction, thermal analysis, and metallographic studies indicate that the germanium-rich liquid freezes as essentially pure germanium and that the solid solubility of germanium in boron and of boron in germanium is virtually nil at the eutectic temperature. The minute quantity of boron that does dissolve in solid germanium does so substitutionally with a 0.01 to 0.02 volume percent contraction of the germanium lattice. These results indicate that germanium may have utility as a boron diffusion barrier for boron fiber-reinforced metal-matrix composites. (Author)

Descriptors :   (*BORON, PHASE STUDIES), (*GERMANIUM, PHASE STUDIES), PHASE DIAGRAMS, SOLUBILITY, DIFFUSION, BARRIER COATINGS, FILAMENTS, REINFORCING MATERIALS, COMPOSITE MATERIALS.

Subject Categories : Physical Chemistry
      Laminates and Composite Materials
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE