Fundamental Atomistic Insights into Tunable Tribological Performance of NbC/Nb Films through Thickness and Depth Effects
Ceramic–metal nanolaminates (CMNLs) are promising scratch-resistant coatings, but knowledge gaps remain regarding the interactive effects of individual layer thickness and scratch depth. This study employed molecular dynamics simulations to investigate the tribological performance of NbC/Nb CMNLs, s...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-12-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/14/1/2 |
| _version_ | 1797343016579497984 |
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| author | Iman Salehinia |
| author_facet | Iman Salehinia |
| author_sort | Iman Salehinia |
| collection | DOAJ |
| description | Ceramic–metal nanolaminates (CMNLs) are promising scratch-resistant coatings, but knowledge gaps remain regarding the interactive effects of individual layer thickness and scratch depth. This study employed molecular dynamics simulations to investigate the tribological performance of NbC/Nb CMNLs, systematically varying ceramic and metal layer thicknesses (0.5–7.5 nm) and scratch depths (3, 5 nm). Models were loaded under displacement-controlled indentation followed by scratching. Mechanical outputs like material removal, friction coefficients, normal, and friction forces quantified scratch resistance. Material removal was even below that for NbC alone, demonstrating the multilayer benefit. Thinner layers showed complete penetration by the indenter, with material rolled in front rather than piled up. Thicker layers resisted penetration, enabling pile-up and lower friction coefficients due to higher normal forces. Excessive material removal decreased normal forces and raised friction coefficients. Peak coefficient occurred around 1.5–3 nm layer thicknesses where substantial top layer volumes were removed, minimizing ceramic under the indenter. Layer thickness corresponding to lowest material removal depended on scratch depth, with 3 nm and 7.5 nm layer thickness for 3 and 5 nm depths, respectively. Metallic layers reduced stiffness and drove material downward over piling up. Quantifying scratch resistance versus geometric parameters elucidates fundamental physics to facilitate superior CMNL coating fabrication. |
| first_indexed | 2024-03-08T10:41:34Z |
| format | Article |
| id | doaj.art-ba6ae50da9964022a5acfb6eb8c3f42c |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-08T10:41:34Z |
| publishDate | 2023-12-01 |
| publisher | MDPI AG |
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| series | Metals |
| spelling | doaj.art-ba6ae50da9964022a5acfb6eb8c3f42c2024-01-26T17:39:23ZengMDPI AGMetals2075-47012023-12-01141210.3390/met14010002Fundamental Atomistic Insights into Tunable Tribological Performance of NbC/Nb Films through Thickness and Depth EffectsIman Salehinia0Department of Mechanical Engineering, Northern Illinois University, DeKalb, IL 60115, USACeramic–metal nanolaminates (CMNLs) are promising scratch-resistant coatings, but knowledge gaps remain regarding the interactive effects of individual layer thickness and scratch depth. This study employed molecular dynamics simulations to investigate the tribological performance of NbC/Nb CMNLs, systematically varying ceramic and metal layer thicknesses (0.5–7.5 nm) and scratch depths (3, 5 nm). Models were loaded under displacement-controlled indentation followed by scratching. Mechanical outputs like material removal, friction coefficients, normal, and friction forces quantified scratch resistance. Material removal was even below that for NbC alone, demonstrating the multilayer benefit. Thinner layers showed complete penetration by the indenter, with material rolled in front rather than piled up. Thicker layers resisted penetration, enabling pile-up and lower friction coefficients due to higher normal forces. Excessive material removal decreased normal forces and raised friction coefficients. Peak coefficient occurred around 1.5–3 nm layer thicknesses where substantial top layer volumes were removed, minimizing ceramic under the indenter. Layer thickness corresponding to lowest material removal depended on scratch depth, with 3 nm and 7.5 nm layer thickness for 3 and 5 nm depths, respectively. Metallic layers reduced stiffness and drove material downward over piling up. Quantifying scratch resistance versus geometric parameters elucidates fundamental physics to facilitate superior CMNL coating fabrication.https://www.mdpi.com/2075-4701/14/1/2scratch behaviorceramic/metal nano-laminateslayer thicknesspenetration depthfriction coefficientmaterial removal |
| spellingShingle | Iman Salehinia Fundamental Atomistic Insights into Tunable Tribological Performance of NbC/Nb Films through Thickness and Depth Effects Metals scratch behavior ceramic/metal nano-laminates layer thickness penetration depth friction coefficient material removal |
| title | Fundamental Atomistic Insights into Tunable Tribological Performance of NbC/Nb Films through Thickness and Depth Effects |
| title_full | Fundamental Atomistic Insights into Tunable Tribological Performance of NbC/Nb Films through Thickness and Depth Effects |
| title_fullStr | Fundamental Atomistic Insights into Tunable Tribological Performance of NbC/Nb Films through Thickness and Depth Effects |
| title_full_unstemmed | Fundamental Atomistic Insights into Tunable Tribological Performance of NbC/Nb Films through Thickness and Depth Effects |
| title_short | Fundamental Atomistic Insights into Tunable Tribological Performance of NbC/Nb Films through Thickness and Depth Effects |
| title_sort | fundamental atomistic insights into tunable tribological performance of nbc nb films through thickness and depth effects |
| topic | scratch behavior ceramic/metal nano-laminates layer thickness penetration depth friction coefficient material removal |
| url | https://www.mdpi.com/2075-4701/14/1/2 |
| work_keys_str_mv | AT imansalehinia fundamentalatomisticinsightsintotunabletribologicalperformanceofnbcnbfilmsthroughthicknessanddeptheffects |