Substrate surface finish effects on scratch resistance and failure mechanisms of TiN-coated hardmetals

SURFACE & COATINGS TECHNOLOGY

卷:265

Article

Yang, J.^1,2  Roa, J. J.^1,3  Oden, M.²  Johansson-Joesaar, M. P.^2,4  Esteve, J.⁵  Llanes, L.^1,3 

[1] Univ Politecn Cataluna, ETSEIB, CIEFMA, Dept Ciencia Dels Mat & Engn Met, E-08028 Barcelona, Spain

[2] Linkoping Univ, Nanostruct Mat, Dept Phys Chem & Biol IFM, S-58183 Linkoping, Sweden

[3] Univ Politecn Cataluna, CRnE, Ctr Res Nanoengn, E-08028 Barcelona, Spain

[4] SECO Tools AB, Fagersta 73782, Sweden

[5] Univ Barcelona, Dept Fis Aplicada & Opt, E-08028 Barcelona, Spain

关键词: Scratch resistance;    Substrate surface finish;    Grinding;    Coated hardmetal;    Scratch failure mechanisms;   

DOI  :  10.1016/j.surfcoat.2015.01.038

来源: Elsevier

【 摘 要 】

In this study, the influence of substrate surface finish on scratch resistance and associated failure mechanisms is investigated in the case of a TiN-coated hardmetal. Three different surface finish conditions are studied: as-sintered (AS), ground (G), and mirror-like polished (P). For G conditioned samples, scratch tests are conducted both parallel and perpendicular to the direction of the grinding grooves. It is found that coated AS, G and P samples exhibit similar critical load for initial substrate exposure and the same brittle adhesive failure mode. However, the damage scenarios are different, i.e. the substrate exposure is discrete and localized to the scratch tracks for G samples while a more pronounced and continuous exposure is seen for AS and P ones. Aiming to understand the role played by the grinding-induced compressive residual stresses, the study is extended to coated systems where ground substrates are thermal annealed (for relieving stresses) before being ion etched and coated. It yielded lower critical loads and changes in the mechanisms for the scratch-related failure; the latter depending on the relative orientation between scratching and grinding directions. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free