Radiation induced hardening of beryllium during low temperature He implantation

The effect of ion irradiation on evolution of microstructure and hardening of beryllium with different impurity levels was investigated using TEM and nanoindentation. High purity S-65 grade and less-pure S-200-F grade were implanted by helium ions at temperatures of 50°C and 200°C....

Full description

Bibliographic Details
Main Authors: Kuksenko, V, Lunev, A, Darnbrough, E, Densham, C, Hurh, P, Roberts, S
Format: Journal article
Language:English
Published: Elsevier 2021
_version_ 1826304073342648320
author Kuksenko, V
Lunev, A
Darnbrough, E
Densham, C
Hurh, P
Roberts, S
author_facet Kuksenko, V
Lunev, A
Darnbrough, E
Densham, C
Hurh, P
Roberts, S
author_sort Kuksenko, V
collection OXFORD
description The effect of ion irradiation on evolution of microstructure and hardening of beryllium with different impurity levels was investigated using TEM and nanoindentation. High purity S-65 grade and less-pure S-200-F grade were implanted by helium ions at temperatures of 50°C and 200°C. 11 different energies were used, so as to create a quasi-homogeneous 3 µm irradiated layer with average radiation damage of 0.1 dpa and average He content of 2000 appm. Nanoindentation experiments demonstrated that before irradiation, the S-200-F and S-65 grades have an average hardness of 3.7±0.8 GPa and 3.4±0.8 GPa correspondently. After implantation the hardness of both grades increased by about 60% for the 200°C irradiation and 100% for the 50°C irradiation. The crystallographic analysis of indented grains demonstrated that in the as-received materials the hardness is about 2.5 times higher when the indentation direction is close to the [0001] c-axis of beryllium compared to indentation perpendicular to [0001]. Hardness anisotropy significantly decreased after irradiation: the “soft orientation” was most sensitive to irradiation-induced hardening, with hardness increasing by about 140% after irradiation at 50°C and 100% after irradiation at 200°C, compared to about 15 - 20% for the “hard” orientation at both irradiation temperatures. The higher purity grade had smaller increase of the “soft orientation” hardness: 2.5±0.3 GPa for the S-65 and 2.9±0.2 GPa for the S-200-F. At both temperatures in both grades, under TEM investigation the radiation damage appears as “black dots” which are likely to be small dislocation loops with the number density of ~ 1022 m−3. No bubbles were observed by TEM inside grains and at grain boundaries. Analysis of the possible hardening contribution demonstrated that the observed “black dots” could be responsible for up to half of the measured hardening, while the rest of the hardening should originate from helium bubbles with the size below the TEM resolution (at or below 1.5 nm).
first_indexed 2024-03-07T06:12:16Z
format Journal article
id oxford-uuid:efee625c-330e-4c14-8a92-95df5c9b92dc
institution University of Oxford
language English
last_indexed 2024-03-07T06:12:16Z
publishDate 2021
publisher Elsevier
record_format dspace
spelling oxford-uuid:efee625c-330e-4c14-8a92-95df5c9b92dc2022-03-27T11:43:52ZRadiation induced hardening of beryllium during low temperature He implantationJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:efee625c-330e-4c14-8a92-95df5c9b92dcEnglishSymplectic ElementsElsevier2021Kuksenko, VLunev, ADarnbrough, EDensham, CHurh, PRoberts, SThe effect of ion irradiation on evolution of microstructure and hardening of beryllium with different impurity levels was investigated using TEM and nanoindentation. High purity S-65 grade and less-pure S-200-F grade were implanted by helium ions at temperatures of 50°C and 200°C. 11 different energies were used, so as to create a quasi-homogeneous 3 µm irradiated layer with average radiation damage of 0.1 dpa and average He content of 2000 appm. Nanoindentation experiments demonstrated that before irradiation, the S-200-F and S-65 grades have an average hardness of 3.7±0.8 GPa and 3.4±0.8 GPa correspondently. After implantation the hardness of both grades increased by about 60% for the 200°C irradiation and 100% for the 50°C irradiation. The crystallographic analysis of indented grains demonstrated that in the as-received materials the hardness is about 2.5 times higher when the indentation direction is close to the [0001] c-axis of beryllium compared to indentation perpendicular to [0001]. Hardness anisotropy significantly decreased after irradiation: the “soft orientation” was most sensitive to irradiation-induced hardening, with hardness increasing by about 140% after irradiation at 50°C and 100% after irradiation at 200°C, compared to about 15 - 20% for the “hard” orientation at both irradiation temperatures. The higher purity grade had smaller increase of the “soft orientation” hardness: 2.5±0.3 GPa for the S-65 and 2.9±0.2 GPa for the S-200-F. At both temperatures in both grades, under TEM investigation the radiation damage appears as “black dots” which are likely to be small dislocation loops with the number density of ~ 1022 m−3. No bubbles were observed by TEM inside grains and at grain boundaries. Analysis of the possible hardening contribution demonstrated that the observed “black dots” could be responsible for up to half of the measured hardening, while the rest of the hardening should originate from helium bubbles with the size below the TEM resolution (at or below 1.5 nm).
spellingShingle Kuksenko, V
Lunev, A
Darnbrough, E
Densham, C
Hurh, P
Roberts, S
Radiation induced hardening of beryllium during low temperature He implantation
title Radiation induced hardening of beryllium during low temperature He implantation
title_full Radiation induced hardening of beryllium during low temperature He implantation
title_fullStr Radiation induced hardening of beryllium during low temperature He implantation
title_full_unstemmed Radiation induced hardening of beryllium during low temperature He implantation
title_short Radiation induced hardening of beryllium during low temperature He implantation
title_sort radiation induced hardening of beryllium during low temperature he implantation
work_keys_str_mv AT kuksenkov radiationinducedhardeningofberylliumduringlowtemperatureheimplantation
AT luneva radiationinducedhardeningofberylliumduringlowtemperatureheimplantation
AT darnbroughe radiationinducedhardeningofberylliumduringlowtemperatureheimplantation
AT denshamc radiationinducedhardeningofberylliumduringlowtemperatureheimplantation
AT hurhp radiationinducedhardeningofberylliumduringlowtemperatureheimplantation
AT robertss radiationinducedhardeningofberylliumduringlowtemperatureheimplantation