Any type of irradiation that displaces atoms can produce voids in non-fissile metals and alloys, consequent swelling and mechanical property effects becoming important in fast reactor design and operation. The basic reason for void formation is preferential absorption of interstitials at dislocations. Void growth depends on competition between alternative sinks for diffusing vacancies and interstitials. Irradiation and materials variables affect void formation through both the point defect behaviour and the dislocation behaviour. Void ordering and annealing effects are also discussed.

Voids in irradiated metals. part i.

High‐energy radiation simultaneously produces vacancies and interstitials in crystalline materials and, therefore, both types of defects are supersaturated during irradiation. The nucleation of defect precipitates under this circumstance is fundamentally different from the usual nucleation problem because of the competing effects of interstitials and vacancies on the size distribution of precipitate embryos. The rate of homogeneous nucleation of voids in such a material in which interstitials as well as vacancies are supersaturated is derived in this paper. It is shown that the thermodynamically derivable void embryo size distribution n0(x) (that is, the distribution which is in equilibrium with a given vacancy supersaturation) is in equilibrium with interstitials only when the latter are in equilibrium with the vacancies, i.e., when the interstitials are undersaturated to the same extent as the vacancies are supersaturated. The constrained distribution of voids n(x) (that is, when the interstitials are a...

Nucleation of Voids in Materials Supersaturated with Vacancies and Interstitials

The defect structure in α-titanium and rhenium irradiated with neutrons at 04T m (T m = absolute melting temperature) has been analyzed using transmission electron microscopy In rhenium, the vacancies agglomerate into voids whereas in titanium, vacancy dislocation loops lying on the prism planes are the only vacancy type defects observed In both metals, dislocation segments and network fragments are the main evidence of interstitial type defects The presence of dislocation loops rather than voids in titanium irradiated at this temperature is an anamalous result when compared to results on other similarly irradiated pure metals Possible explanations for the preferential formation of loops rather than voids in the titanium are discussed

Microstructural analysis of neutron irradiated titanium and rhenium

The effects of large fast-neutron fluences on the structure of stainless steel

This chapter is a review of the properties and performance of aluminum alloys during service in water-cooled research reactors. Typical applications are listed. The attributes and limitations of aluminum for reactor use are discussed. Fuel cladding and corrosion aspects are discussed. Development of radiation damage microstructure and changes in mechanical properties are outlined.

E.L. Long

Papers

High-neutron fluence damage in an aluminum alloy☆

Annealing of voids in aluminum.