Structure and properties of Nb-Ge and Nb-Sn alloys synthesized by mechanical alloying

Thesis/Dissertation · Thu Jan 01 00:00:00 EST 1987

OSTI ID:6695966

Kim, M S

The principal objective of this research was the comparison of the structure and selected properties of amorphous alloys made by mechanical alloying with amorphous alloys of the same compositions made by vapor-quenching techniques. In addition, characterization of these amorphous materials in terms of structural model, powder morphology, hardness, and Moessbauer spectroscopy, and superconductivity was conducted. Many useful combinations of metals can not be achieved by melt or by conventional powder metallurgy. Such materials can be made by cold-welding metal powders in a special high-energy ball mill - mechanical alloying (MA). The Nb-Ge and Nb-Sn model systems were chosen for study. The measurements of the stability of the amorphous phases in Nb-25 at. % Ge and Nb-27 at. % Ge alloys were made by differential scanning calorimetry (DSC). X-ray diffraction was used to follow the progress of the average structure during MA and to determine the structures of the phases formed after crystallization. It was found that the MA technique is applicable to production of amorphous structure in non-glass forming systems, (Nb-Sn and Nb-Ge). These amorphous phases were shown to exhibit a similar T/sub c/ when compared with a material obtained by vapor-quenching technique.

• Research Organization: North Carolina State Univ., Raleigh (USA)
• OSTI ID: 6695966
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
GERMANIUM ALLOYS
FABRICATION
NIOBIUM ALLOYS
TIN ALLOYS
AMORPHOUS STATE
MECHANICAL PROPERTIES
PHASE STUDIES
SUPERCONDUCTIVITY
ALLOYS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
PHYSICAL PROPERTIES
360101* - Metals & Alloys- Preparation & Fabrication
360102 - Metals & Alloys- Structure & Phase Studies
360104 - Metals & Alloys- Physical Properties