Atom Probe Tomography investigations on grain boundary segregation in polycrystalline Ti(C,N) and Zr(C,N) CVD coatings

SCRIPTA MATERIALIA

卷:162

Article

El Azhari, Idriss^1,2,3  Barrirero, Jenifer^1,3  Garcia, Jose⁴  Soldera, Flavio^1,3  Llanes, Luis²  Muecklich, Frank^1,3 

[1] Saarland Univ, Funct Mat, Dept Mat Sci & Engn, Campus D 3-3, D-66123 Saarbrucken, Germany

[2] Univ Politecn Cataluna, Mat Sci & Met Dept CIEFMA, Barcelona East Sch Engn EEBE, Barcelona 08019, Spain

[3] MECS, D-66125 Saarbrucken, Germany

[4] Sandvik Coromant R&D, SE-12680 Stockholm, Sweden

关键词: CVD polycrystalline coatings;    Atom Probe Tomography;    Grain boundary segregation;    Chlorine;    Cobalt;   

DOI  :  10.1016/j.scriptamat.2018.11.041

来源: Elsevier

【 摘 要 】

Atom Probe Tomography (APT) was used to obtain a direct evidence of chlor segregation and cobalt diffusion at the grain boundaries (GBs) of polycrystalline coatings deposited by moderate temperature chemical vapor deposition (MT-CVD) on a WC-Co cemented carbide substrate. Reasons behind segregations are discussed, and its effects are correlated to the micromechanical properties of Ti(C,N) and Zr(C,N). It is concluded that chlorine segregation is a relevant factor for explaining the low cohesive strength at the GBs of Ti(C,N) leading to intergranular failure during micro-compression testing, while its absence in Zr(C,N) along with Co diffusion contribute to grain boundary strengthening. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

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