Radiation effects on microstructure and hardness of a titanium aluminide alloy irradiated by helium ions at room and elevated temperatures
Radiation effects on microstructure and hardness of a titanium aluminide alloy irradiated by helium ions at room and elevated temperatures
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DOI：
10.1016/j.jnucmat.2015.01.043
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发表时间：
2015-04
影响因子：
3.1
通讯作者：
Tao Wei;Hanliang Zhu;M. Ionescu;P. Dayal;Joel Davis;D. Carr;R. Harrison;L. Edwards
中科院分区：
文献类型：
--
作者：
Tao Wei;Hanliang Zhu;M. Ionescu;P. Dayal;Joel Davis;D. Carr;R. Harrison;L. Edwards
采用5mev氦离子辐照45XD层状TiAl合金，辐照量为5 × 1021ion m−2(5000 appm)，辐照剂量约为1dpa（每原子位移）。通过施加能量降解轮，在距靶表面约17 μm处形成了均匀的氦离子停止损伤区域。在室温辐照下，样品的微观结构中存在氦空位团簇和小氦泡等辐射损伤缺陷。随着辐照温度的升高（300℃和500℃），辐照组织的α2相和γ相均出现了明显的氦泡。采用纳米压痕法测定了辐照硬化的效果。室温下辐照的样品硬度从5.6 GPa增加到8.5 GPa， 300℃和500℃辐照的样品的辐照硬化效应降低到约8.0 GPa。
A 45XD TiAl alloy possessing a lamellar microstructure was irradiated using 5 MeV helium ions to a fluence of 5 × 1021ion m−2(5000 appm) with a dose of about 1 dpa (displacements per atom). A uniform helium ion stopping damage region about 17 μm deep from the target surface was achieved by applying an energy degrading wheel. Radiation damage defects including helium-vacancy clusters and small helium bubbles were found in the microstructure of the samples irradiated at room temperature. With increasing irradiation temperature to 300 °C and 500 °C helium bubbles were clearly observed in both the α2and γ phases of the irradiated microstructure. By means of nanoindentation significant irradiation hardening was measured. For the samples irradiated at room temperature the hardness increased from 5.6 GPa to 8.5 GPa and the irradiation-hardening effect reduced to approximately 8.0 GPa for the samples irradiated at 300 °C and 500 °C.