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Title: Cavity morphology in a Ni based superalloy under heavy ion irradiation with hot pre-injected helium. II

In the current investigation, TEM in-situ heavy ion (1 MeV Kr{sup 2+}) irradiation with helium pre-injected at elevated temperature (400 °C) was conducted to simulate in-reactor neutron irradiation induced damage in CANDU spacer material Inconel X-750, in an effort to understand the effects of helium on irradiation induced cavity microstructures. Three different quantities of helium, 400 appm, 1000 appm, and 5000 appm, were pre-injected directly into TEM foils at 400 °C. The samples containing helium were then irradiated in-situ with 1 MeV Kr{sup 2+} at 400 °C to a final dose of 5.4 dpa (displacement per atom). Cavities were formed from the helium injection solely and the cavity density and size increased with increasing helium dosage. In contrast to previous heavy ion irradiations with cold pre-injected helium, heterogeneous nucleation of cavities was observed. During the ensuing heavy ion irradiation, dynamical observation showed noticeable size increase in cavities which nucleated close to the grain boundaries. A “bubble-void” transformation was observed after Kr{sup 2+} irradiation to high dose (5.4 dpa) in samples containing 1000 appm and 5000 appm helium. Cavity distribution was found to be consistent with in-reactor neutron irradiation induced cavity microstructures. This implies that the distribution of helium is greatly dependent on the injection temperature, andmore » helium pre-injection at high temperature is preferred for simulating the migration of the transmutation produced helium.« less
Authors:
; ;  [1] ;  [2]
  1. Department of Mechanical and Materials Engineering, Queen's University Kingston, Ontario K7L 3N6 (Canada)
  2. Material Science Division, Argonne National Laboratory Argonne, Illinois 60439 (United States)
Publication Date:
OSTI Identifier:
22277896
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 10; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; ATOMIC DISPLACEMENTS; DENSITY; GRAIN BOUNDARIES; HELIUM; INCONEL ALLOYS; IRRADIATION; KRYPTON IONS; MORPHOLOGY; NEUTRON FLUENCE; NUCLEATION; RADIATION DOSES; TRANSMISSION ELECTRON MICROSCOPY