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论文类型：期刊论文

发表时间：2017-09-15

发表刊物：APPLIED SURFACE SCIENCE

收录刊物：SCIE、EI、Scopus

卷号：416

页面范围：891-900

ISSN号：0169-4332

关键字：Hardness; Cyclic loading; Nickel alloy; Transmission electron microscopy; Indentation

摘要：Nanotwinned (NT) surfaces are developed on a face-centered cubic (fcc) metal with ultrahigh hardness under cyclic loading using plastic deformation at room temperature. The hardness on NT surfaces remains constant at 7.9 and 8.5 GPa indented at 1 and 7 N under 0-100 cycles respectively, which are about three times that of their pristine surfaces. This is different from the NT metals and nonmetallic materials, on which the hardness is about two times that of their pristine counterparts. Moreover, NT metals usually consist of randomly oriented twin and grain boundaries, making it difficult to control the uniform mechanical property. Here, novel nt structure is proposed on an fcc metal, in which all the twin boundaries are along (-1-11) orientation, forming bundles of nanotwins to several micrometers in length. (C) 2017 Elsevier B.V. All rights reserved.