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Showing 1 to 9 of 9 for “"positron annihilation spectroscopy"”.
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Positron annihilation spectroscopy to understand defect formation and evolution in neutron-irradiated Fe-Cr model alloys
Positron annihilation spectroscopy (PAS) is a powerful, non-destructive technique used to characterize the defect properties of materials. There are two major types of PAS, positron annihilation lifetime spectroscopy and Doppler broadening spectroscopy (DBS). This work focused on the latter. DBS …
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Residual stress measurements and analysis by destructive and non-destructive techniques
… ring-core (RC), neutron diffraction (ND) and positron annihilation spectroscopy (PAS). The results obtained by the PAS method indicate that the residual stresses in the cold-worked specimens were significantly enhanced with increased level of cold reduction. Residual stress measurements by the …
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Metallurgical characterization and residual stress measurements of target structural materials
… method and nondestructive techniques including positron annihilation spectroscopy (PAS), neutron diffraction (ND) and x-ray diffraction (XRD) methods. Materials tested were austenitic Type 304L SS and martensitic Alloys EP-823 and HT-9. Types of specimen tested include cold-worked (CW), …
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Comparative analyses of residual stresses in target sub-system materials
… to those obtained by other techniques including positron annihilation spectroscopy, x-ray diffraction and ring-core methods. Cold-worked (CW), three-point-bent (TPB) and welded specimens of similar and dissimilar materials were tested. ND measurements on CW specimens showed enhanced residual …
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Thermal and transport properties of layered silicate nanomaterials subjected to extreme thermal cycling
… addition of the nanoclays in the nanocomposites. Positron annihilation spectroscopy (PAS) was utilized to comprehend how the distribution of the free volume was affected by the presence of the nanoclays and by the thermal cycling applied. Different permeability models were utilized in an attempt …
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Some effects on polymers of low-energy implanted positrons
The positron annihilation spectroscopy is a well established non-destructive tool to characterize materials and defects. Low-energy positron beams are suitable for thin-layer materials because a defined penetration depth of positrons can be obtained. This thesis is focused on two issues: 1. The …
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Positron Annihilation lifetime studies of inorganic materials using a new positron beamline
… unique information about a target sample, is Positron Annihilation Spectroscopy (PAS). The initial aim of the research presented here was the development and characterisation of a positron beamline for materials studies. This beamline, now operational, has been developed to measure the …
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Positron Annihilation lifetime studies of inorganic materials using a new positron beamline
… unique information about a target sample, is Positron Annihilation Spectroscopy (PAS). The initial aim of the research presented here was the development and characterisation of a positron beamline for materials studies. This beamline, now operational, has been developed to measure the …