Dendritic growth of voids in irradiated nickel--aluminum alloys

Journal Article · Mon Nov 01 04:00:00 EST 1976 · Scr. Metall.; (United States)

DOI:https://doi.org/10.1016/0036-9748(76)90126-5· OSTI ID:7313291

Chen, L J; Ardell, A J

Void morphology suggestive of dendritic growth observed in ion irradiated Ni-Al alloys is described. Observations of dendritic voids provide rather strong, although indirect, evidence for interface-reaction controlled void growth, at least during the early stages of swelling. This is because the shape instability that changes a polyhedron into a dendrite is consistent with the theoretically expected, and experimentally observed, transition from interface-reaction controlled to diffusion-controlled growth. The interface-reaction in this case is the lateral spreading process. Al additions lower the steady-state vacancy concentration, c/sub v/, at a given temperature and dose rate promoting the onset of dendritic growth. There is evidence that this occurs because of the observation that void growth rates in Ni-Al alloys decrease as the Al content increases; lowering c/sub v/ is one way to account for this. Consequently, a reduction in c/sub v/ simultaneously lowers the void growth rate and the critical size for the onset of dendritic growth. Whereas the simplicity of this explanation is appealing, it is believed that the conditions governing the onset of morphological instability are complicated by the effects of irradiation-induced solute segregation, which have been observed in several other alloys. (JRD)

• Research Organization: Univ. of California, Los Angeles
• OSTI ID: 7313291
• Journal Information: Scr. Metall.; (United States), Journal Name: Scr. Metall.; (United States) Vol. 10:11; ISSN SCRMB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360106* -- Metals & Alloys-- Radiation Effects
ALLOYS
ALUMINIUM ALLOYS
ATOMIC IONS
BEAMS
CHARGED PARTICLES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DENDRITES
DIFFUSION
ENERGY RANGE
ION BEAMS
IONS
MEV RANGE
MEV RANGE 01-10
NICKEL ALLOYS
NICKEL BASE ALLOYS
NICKEL IONS
PHYSICAL RADIATION EFFECTS
POINT DEFECTS
RADIATION EFFECTS
SWELLING
VACANCIES
VOIDS