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Papers by David Frazer

Research paper thumbnail of Micro mechanical testing of candidate structural alloys for Gen-IV nuclear reactors

Nuclear Materials and Energy, 2018

Ion irradiation is often used to simulate the effects of neutron irradiation due to reduced activ... more Ion irradiation is often used to simulate the effects of neutron irradiation due to reduced activation of materials and vastly increased dose rates. However, the low penetration depth of ions requires the development of smallscale mechanical testing techniques, such as nanoindentation and microcompression, in order to measure mechanical properties of the irradiated material. In this study, several candidate structural alloys for Gen-IV reactors (800H, T91, nanocrystalline T91 and 14YWT) were irradiated with 70 MeV Fe 9+ ions at 452°C to an average damage of 20.68 dpa. Both the nanoindentation and microcompression techniques revealed significant irradiation hardening and an increase in yield stress after irradiation in austenitic 800H and ferritic-martensitic T91 alloys. Ion irradiation was observed to have minimal effect on the mechanical properties of nanocrystalline T91 and oxide dispersion strengthened 14YWT. These observations are further supported by line broadening analysis of X-ray diffraction measurements, which show a significantly smaller increase in dislocation density in the 14YWT and nanocrystalline T91 alloys after irradiation. In addition, good agreement was observed between cross-sectional nanoindentation and the damage profile from SRIM calculations.

Research paper thumbnail of Liquid metal as a heat transport fluid for thermal solar power applications

Research paper thumbnail of Oxide scale formation on 316L and FeCrAl steels exposed to oxygen controlled static LBE at temperatures up to 800°C

The corrosion behavior of three stainless steels (316L, Alkrothal 720 and Kanthal-APM) in static ... more The corrosion behavior of three stainless steels (316L, Alkrothal 720 and Kanthal-APM) in static LBE with oxygen concentration of 10 À 5 wt% at temperatures of 700°C for 230 h and 800°C for 360 h was studied. The steel surface morphology of the oxide scales formed was investigated by SEM, XRD and Raman spectroscopy and the cross-section by SEM and EDX. A transitional inner-layer of Fe-Cr-Al oxides was found at the substrate interface and an Al-oxide outer layer on the Fe-Cr-Al alloys. Fast growing nonprotective oxide scale with underlying dissolution was observed on the 316L alloy.

Research paper thumbnail of Localized mechanical property assessment of SiC/SiC composite materials

Composites Part A: Applied Science and Manufacturing, 2014

Research paper thumbnail of Evaluation of the mechanical properties of naturally grown multilayered oxides formed on HCM12A using small scale mechanical testing

Research paper thumbnail of Oxide scale formation on 316L and FeCrAl steels exposed to oxygen controlled static LBE at temperatures up to 800°C

Research paper thumbnail of Essential aspects of controlling the oxygen content of molten tin in engineering applications

Research paper thumbnail of Micro mechanical testing of candidate structural alloys for Gen-IV nuclear reactors

Nuclear Materials and Energy, 2018

Ion irradiation is often used to simulate the effects of neutron irradiation due to reduced activ... more Ion irradiation is often used to simulate the effects of neutron irradiation due to reduced activation of materials and vastly increased dose rates. However, the low penetration depth of ions requires the development of smallscale mechanical testing techniques, such as nanoindentation and microcompression, in order to measure mechanical properties of the irradiated material. In this study, several candidate structural alloys for Gen-IV reactors (800H, T91, nanocrystalline T91 and 14YWT) were irradiated with 70 MeV Fe 9+ ions at 452°C to an average damage of 20.68 dpa. Both the nanoindentation and microcompression techniques revealed significant irradiation hardening and an increase in yield stress after irradiation in austenitic 800H and ferritic-martensitic T91 alloys. Ion irradiation was observed to have minimal effect on the mechanical properties of nanocrystalline T91 and oxide dispersion strengthened 14YWT. These observations are further supported by line broadening analysis of X-ray diffraction measurements, which show a significantly smaller increase in dislocation density in the 14YWT and nanocrystalline T91 alloys after irradiation. In addition, good agreement was observed between cross-sectional nanoindentation and the damage profile from SRIM calculations.

Research paper thumbnail of Liquid metal as a heat transport fluid for thermal solar power applications

Research paper thumbnail of Oxide scale formation on 316L and FeCrAl steels exposed to oxygen controlled static LBE at temperatures up to 800°C

The corrosion behavior of three stainless steels (316L, Alkrothal 720 and Kanthal-APM) in static ... more The corrosion behavior of three stainless steels (316L, Alkrothal 720 and Kanthal-APM) in static LBE with oxygen concentration of 10 À 5 wt% at temperatures of 700°C for 230 h and 800°C for 360 h was studied. The steel surface morphology of the oxide scales formed was investigated by SEM, XRD and Raman spectroscopy and the cross-section by SEM and EDX. A transitional inner-layer of Fe-Cr-Al oxides was found at the substrate interface and an Al-oxide outer layer on the Fe-Cr-Al alloys. Fast growing nonprotective oxide scale with underlying dissolution was observed on the 316L alloy.

Research paper thumbnail of Localized mechanical property assessment of SiC/SiC composite materials

Composites Part A: Applied Science and Manufacturing, 2014

Research paper thumbnail of Evaluation of the mechanical properties of naturally grown multilayered oxides formed on HCM12A using small scale mechanical testing

Research paper thumbnail of Oxide scale formation on 316L and FeCrAl steels exposed to oxygen controlled static LBE at temperatures up to 800°C

Research paper thumbnail of Essential aspects of controlling the oxygen content of molten tin in engineering applications

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