Electron irradiation induced crystalline to amorphous transition in Cu-Ti intermetallic compounds

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6954901

Luzzi, D E

The electron irradiation induced crystalline to amorphous (C-A) transition in intermetallic compounds is studied using in-situ imaging and diffraction experiments in a 3-MV high voltage electron microscopy as well as high resolution electron microscopy of the crystalline/amorphous boundary region coupled with optical diffraction analysis. The C-A transition is a dose-dependent process. Thus, it is driven by the energy increase in the density of point defects. Experimental evidence and energy arguments indicate that models based on point defects are unsatisfactory. In-situ measurements of irradiation induced chemical disordering are done in intermetallic compounds of the Cu-Ti alloy system. Critical temperatures for chemical disordering and amorphization are found and they are coincident, T/sub c/, significant chemical disordering always precedes a complete C-A transition. Above T/sub c/, the degree of chemical disordering is greatly reduced and only secondary defects are produced. These results indicate that the chemical disordering plays the major role in driving the transition. Chemical reordering due to the migration of point defects competes with the chemical disordering, preventing a sufficient energy increase of the crystal at temperatures above T/sub c/.

• Research Organization: Northwestern Univ., Evanston, IL (USA)
• OSTI ID: 6954901
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360106* -- Metals & Alloys-- Radiation Effects
ALLOYS
AMORPHOUS STATE
BEAMS
COPPER ALLOYS
CRITICAL TEMPERATURE
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTRON BEAMS
ENERGY RANGE
INTERMETALLIC COMPOUNDS
LEPTON BEAMS
MEV RANGE
MEV RANGE 01-10
PARTICLE BEAMS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
RADIATION EFFECTS
THERMODYNAMIC PROPERTIES
TITANIUM ALLOYS
TRANSITION TEMPERATURE