Application of positron annihilation line-shape analysis to fatigue damage for nuclear plant materials

Characterisation of β-quenched and thermally aged Zircaloy-2 by positron annihilation, hardness and ultrasonic velocity measurements

“…Based on the nature of defects, the sensitivity of each of these measurements may vary. For example, investigation of early stages of fatigue damage and the evolution of defect complexes has been reported in reactor alloys using lineshape Sparameter measurements [6]. In these studies, it is found that S-parameter is very sensitive to the variation of dislocation density in early stages but exhibits a saturation behaviour at later stages of fatigue life, due to the loss of sensitivity during the crack initiation and growth stages.…”

A review of non-destructive techniques for the detection of creep damage in power plant steels

“…Portable systems have been developed and their use has been documented for the study of plastic deformation or fatigue damage [140][141][142][143][144][145], but to the best of our knowledge no results have been published on their use for the detection of creep damage.…”

“…Finally, it should be mentioned that this technique can inspect only a very thin subsurface layer because of the small penetration depth of the positrons typically ranging between 10 and 200 mm in steels [135,146], and that in fatigue damage studies most of the changes in positron lifetime and Doppler shift are seen in the first 10% of fatigue life, after which the parameters reach saturation [142][143][144].…”

Fatigue Damage Evaluation Using Electron Backscatter Diffraction

“…On the other hand, the bulk damage accumulates continuously from the start of plant operation. The degree of bulk damage can be evaluated by observing the evolution of defects using transmission electron microscopy 17) or by measuring the density of defects using positron annihilation 18) or ultrasonic attenuation. 19) In particular, electron backscatter diffraction (EBSD) is one of the most promising techniques for assessing crystal lattice defects over a large range from several tens of nanometers to several millimeters.…”