Electro-healing cracks in nickel
Electro-healing cracks in nickel
复制标题
镍裂纹的电修复
DOI：
10.1016/j.msea.2012.10.080
复制
发表时间：
2013-01-20
期刊：
影响因子：
6.4
通讯作者：
Lu, K.
中科院分区：
文献类型：
--
作者：
Zheng, X. G.;Shi, Y. -N.;Lu, K.
修复金属材料中的裂纹是具有挑战性的，因为在环境温度附近固态的原子迁移率有限。在本文中，我们开发了一种新的裂纹愈合方法，即利用电解液中的金属离子作为愈合剂的电化学过程。以含穿透裂纹的纯镍板为例进行了分析。尺寸在微米或更大的裂缝可以通过电愈合成功愈合。电修复过程从修复晶体的垂直外延生长开始，从原始裂纹表面开始，然后是修复晶体的横向生长，这些晶体在原子水平上相互结合。拉伸试验表明，固化后的试件具有与原始试件相当的抗拉强度，100微米厚的试件可以获得一定的拉伸延性。断口后分析表明，部分裂纹沿着基材扩展，而不是愈合晶体。随着试件厚度的增加，愈合效率在96%~33%之间，这与完全愈合区域的比例以及基片与愈合晶体之间的强度差有关。(C)2012爱思唯尔B.V.保留所有权利。
Healing cracks in metallic materials is challenging due to limited atomic mobility in solid state around ambient temperature. In this paper, we developed a novel crack-healing approach by means of an electrochemical process in which metallic ions in electrolyte are used as a healing agent. Pure Ni sheets with a through-thickness crack were taken as an example. Cracks with sizes in the micrometer range or larger are successfully healed by electro-healing. The electro-healing process starts with the vertical epitaxial growth of healing, crystals from the original crack surfaces followed by lateral growth of healing crystals that bond with each other at atomistic level. Tensile tests exhibited that the healed samples have a comparable tensile strength as the virgin sample and some tensile ductility can be achieved for the sample of 100 mu m thick. Post-fracture analysis indicated that part of the crack propagated along the substrate instead of healing crystals. The healing efficiency, ranging from 96% to 33% with an increasing sample thickness, is related to the fraction of fully-healed region and the strength difference between the substrate and the healing crystals. (C) 2012 Elsevier B.V. All rights reserved.