Probing fatigue resistance in multi-layer DLC coatings by micro- and nano-impact: Correlation to erosion tests

SURFACE & COATINGS TECHNOLOGY

卷:402

Article

McMaster (Sam), Samuel J.¹  Liskiewicz, Tomasz W.^1,3  Neville, Anne¹  Beake, Ben D.² 

[1] Univ Leeds, Sch Mech Engn, Leeds LS2 9JT, W Yorkshire, England

[2] Micro Mat Ltd, Willow House,Ellice Way, Wrexham LL13 7YL, Wales

[3] Manchester Metropolitan Univ, Fac Sci & Engn, John Dalton Bldg,Chester St, Manchester M15 6BH, Lancs, England

关键词: DLC;    Erosion;    Impact;    Nanoindentation;    Nanomechanics;   

DOI  :  10.1016/j.surfcoat.2020.126319

来源: Elsevier

【 摘 要 】

DLC coatings have seen recent use as protective coatings for flow control devices in the oil and gas industries. Improving fatigue resistance for multi-layered DLC coatings on hardened steel is key for improving their performance in this harsh environment of highly loads repetitive contact. This has been studied directly by microscale repetitive impact tests at significantly higher strain rate and energy than in the nano-impact test, enabling the study of coating fatigue with spherical indenters and dry erosion testing. Nano-impact has also been used to assess the initial fatigue behaviour of the coatings. Good correlation between micro-impact results and erosion results was found. Hard multi-layered a-C:H and Si-a-C:H coatings were found to be significantly less durable under fatigue loading than a-C:H:W. The influence of the coating mechanical properties and structure on these differences is discussed. The results of this study provide further strong evidence that in highly loaded mechanical contact applications requiring a combination of load support and resistance to impact fatigue, the optimum lifetime of coated components may be achieved by designing the coating system to combine these properties rather than by solely aiming to maximise coating hardness as this may be accompanied by brittle fracture and higher wear.

【 授权许可】

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