In situ micro tensile testing of He+2 ion irradiated and implanted single crystal nickel film
In situ micro tensile testing of He+2 ion irradiated and implanted single crystal nickel film
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DOI：
10.1016/j.actamat.2015.08.028
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发表时间：
2015-11-01
期刊：
影响因子：
9.4
通讯作者：
Bhattacharyya, Dhriti
中科院分区：
文献类型：
--
作者：
Reichardt, Ashley;Ionescu, Mihail;Bhattacharyya, Dhriti
利用扫描电子显微镜内的原位微力学测试装置，研究了离子辐照对纯镍单晶拉伸性能的影响。用6 MeV He+2离子辐照（001）面法向12.8 pm厚的Ni薄膜，损伤峰值为10和19个/原子位移（dpa）。利用聚焦离子束（FIB）仪器将平行于薄膜平面的试样制成微拉伸试样，沿[100]方向进行拉伸测试，直至断裂。峰值强度从未辐照时的230 MPa左右增加到10 dpa和19 dpa时的370 MPa和500 MPa左右，而塑性随辐照剂量的增加而降低。峰值损伤区附近的表面以脆性方式断裂，而较小剂量区域的表面则发生了明显的塑性变形。当剂量为19 dpa时，滑移带扩展到峰值损伤区，但没有进一步扩展。透射电镜证实，滑移带在峰值损伤区停止，就在具有空洞或气泡的高浓度区域之前。通过用FIB去除峰值损伤区和He气泡区，可以在整个剩余厚度的样品中实现滑移带的传播。这种材料的去除也使得计算具有峰值硬度的区域的辐照硬化成为可能-从而能够分离高和低损伤区域的硬化效应。版权所有：Elsevier Ltd.代表Acta Materialia Inc.出版版权所有。
The effect of ion irradiation on the tensile properties of pure Ni single crystals was investigated using an in situ micro-mechanical testing device inside a scanning electron microscope. A 12.8 pm-thick Ni film with (001) plane normal was irradiated with 6 MeV He+2 ions to peak damage of 10 and 19 displacements per atom (dpa). Micro-tensile samples were fabricated from the specimens parallel to the plane of the film using a focused ion beam (FIB) instrument, and tested in tension along [100] direction, up to fracture. The peak strength increased from similar to 230 MPa for the unirradiated material to about 370 MPa and 500 MPa for the 10 dpa and 19 dpa samples respectively, while the ductility decreased with increasing dose. The surface near the peak damage regions fractured in a brittle manner, while the regions with smaller dose underwent significant plastic deformation. Slip bands extended to the peak-damage zone in the sample with a dose of 19 dpa, but did not propagate further. Transmission electron microscopy confirmed the stopping of the slip bands at the peak-damage region, just before the high He concentration region with voids or bubbles. By removing the peak damage region and the He bubble region with FIB, it was possible to attain propagation of slip bands through the entire remaining thickness of the sample. This material removal also made it possible to calculate the irradiation hardening in the region with peak hardness - thus enabling the separation of hardening effects in the high and low damage regions. Crown Copyright (C) 2015 Published by Elsevier Ltd. on behalf of Acta Materialia Inc. All rights reserved.