Radiation-induced segregation and precipitation in ion-irradiated molybdenum-rhenium alloys

Thesis/Dissertation · Thu Dec 31 23:00:00 EST 1987

OSTI ID:6883707

Erck, R A

Radiation-induced solute segregation and precipitation in molybdenum-rhenium solid-solution alloys were studied during elevated-temperature helium- and neon-ion irradiation. Radiation-induced segregation of Re atoms in the same direction as the defect fluxes, that is, toward the external surface, was measured during irradiation by in situ Rutherford backscattering spectrometry (RBS). The results of the segregation measurements were in agreement with theoretical models based on point-defect driven transport of solute atoms toward point-defect sinks. After irradiation, near-surface microstructural changes were studied using transmission-electron microscopy (TEM). Radiation-induced chi-phase precipitates were identified. The precipitates adopted coincident and (111) twin orientations with respect to the matrix. The twinning morphology was explained in terms of a coincident-site-lattice model. The results of the RBS and TEM studies constitute strong evidence that precipitation of the chi phase occurs in Mo-Re solid-solution alloys when radiation-induced solute segregation causes the equilibrium solubility limit to be exceeded near point-defect sinks.

• Research Organization: Illinois Univ., Urbana, IL (USA)
• OSTI ID: 6883707
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360106* -- Metals & Alloys-- Radiation Effects
ALLOYS
BEAMS
CHARGED PARTICLES
DISPERSIONS
HELIUM IONS
ION BEAMS
IONS
MIXTURES
MOLYBDENUM ALLOYS
NEON IONS
PHASE STUDIES
PHYSICAL RADIATION EFFECTS
PRECIPITATION
RADIATION EFFECTS
RHENIUM ALLOYS
SEGREGATION
SEPARATION PROCESSES
SOLID SOLUTIONS
SOLUTIONS