Plastic flow at the theoretical yield stress in ceramic films

SCRIPTA MATERIALIA

卷:117

Article

Liu, S.^1,2  Wheeler, J. M.³  Michler, J.³  Zeng, X. T.²  Clegg, W. J.¹ 

[1] Gordon Lab, Dept Mat Sci & Met, 27 Charles Babbage Rd, Cambridge CB3 0FS, England

[2] Singapore Inst Mfg Technol, 71 Nanyang Dr, Singapore 638075, Singapore

[3] EMPA, Swiss Fed Labs Mat Testing & Res, Mat Technol Lab, Feuerwerkerstr 39, CH-3602 Thun, Switzerland

关键词: Hard coating;    Dislocation nucleation;    Micropillar compression;    Deformation kinetics;   

DOI  :  10.1016/j.scriptamat.2016.02.008

来源: Elsevier

【 摘 要 】

Using fine-grained ceramic films based on chromium nitride, and suppressing fracture by using microcompression, it is shown that plastic flow at the theoretical yield stress can be obtained in brittle materials, with shear yield stresses of similar to G/24 at room temperature, which extrapolate to similar to G/19 at 0 K. Surprisingly, it is also found that the rate of deformation, and hence the hardness and the yield stress, are determined not by the soft, glassy grain boundary phase in the fine-grained materials, but by the harder crystal phase. (C) 2015 Elsevier Ltd. All rights reserved.

【 授权许可】

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