Bubbles formation in helium ion irradiated Cu/W multilayer nanocomposites: Effects on structure and mechanical properties
Bubbles formation in helium ion irradiated Cu/W multilayer nanocomposites: Effects on structure and mechanical properties
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DOI：
10.1016/j.jnucmat.2016.02.006
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发表时间：
2016-05-01
影响因子：
3.1
通讯作者：
Polcar, T.
中科院分区：
文献类型：
--
作者：
Callisti, M.;Karlik, M.;Polcar, T.
研究了He气泡对溅射沉积Cu/W多层膜结构和力学性能的影响。沉积了一个周期为10 nm的多层膜，并进行了两种不同影响的氦离子辐照。He气泡主要在Cu层中形成，其分布受He浓度和辐射损伤的影响。根据SRIM计算，在低He浓度区域，气泡主要沿界面形成，而在高He浓度区域，气泡主要沿Cu层和柱状晶界均匀分布。我们认为氦泡的屏蔽效应削弱了界面对点缺陷的湮灭能力。纳米压痕测试显示，在低影响和高影响下，硬度下降幅度分别接近0.5和1 GPa。观察到的软化效应归因于He储存引起的残余应力变化和He气泡促进的柱状晶界/界面滑动。(C) 2016 Elsevier B.V.版权所有
This study investigates the effects of He bubbles on structural and mechanical properties of sputter-deposited Cu/W multilayers. A multilayer with a periodicity of 10 nm was deposited and subjected to helium ion irradiation with two different fluences. He bubbles formed mostly in Cu layers and their distribution was affected by He concentration and radiation damage. According to SRIM calculations, in low He concentration regions bubbles formed mostly along interfaces, while more homogeneously distributed bubbles were found in Cu layers and along columnar grain boundaries in higher He concentration regions. We suggest that the capability of interfaces to annihilate point defects is weakened by the He bubbles shielding effect. Nanoindentation tests revealed a hardness decrease amounting to similar to 0.5 and similar to 1 GPa for low and high fluences, respectively. The observed softening effect is attributed to He storage-induced changes in residual stresses and columnar grain boundary/interfacial sliding facilitated by He bubbles. (C) 2016 Elsevier B.V. All rights reserved.