Unveiling a 72.5 GPa peak hardness in sustainable nanodiamond composite hard coatings via discharge energy control: a nanoindentation-Raman approach.

Egiza, Mohamed; Diab, Mohamed Ragab ; Atta, Hoda; Abdelfatah, Mahmoud M.; El-Shaer, Abdelhamid; Yoshitake, Tsuyoshi

Abstract

Sustainable nanodiamond composite (NDC) films hold promise for high-performance hard coatings thanks to coaxial arc plasma deposition (CAPD). This eco-friendly technique eliminates the need for external heating, chemical reactions, or Co substrate pre-treatment. CAPD boasts lower energy consumption and faster deposition rates, making it a sustainable solution for the growing demand for high-quality, environmentally friendly coatings. This study investigates the influence of discharge energy on the nanostructure and mechanical properties of these NDC films. Optimal discharge energy, ranging from 2.3 to 12 J/pulse, was meticulously explored. A combined nanoindentation-Raman approach reveals a significant correlation between discharge energy and film properties. Remarkably, at 7 J/pulse, a peak hardness of 72.5 GPa is achieved, surpassing other energy levels. Raman spectroscopy confirms maximum nanodiamond content at this energy level (evidenced by maximized Adia/AG ratio, indicating a higher diamond-to-graphite ratio), along with minimal graphitization. Additionally, the presence of trans-polyacetylene (t-PA) peaks (denoted as At-PA) revealed the existence of maximum grain boundaries ratio (At-PA/AG), contributing to enhanced mechanical properties. Optimizing discharge energy tailors NDC film nanostructure, enhancing mechanical performance for advanced hard coatings.

Citation

EGIZA, M., DIAB, M.R., ATTA, H., ABDELFATAH, M.M., EL-SHAER, A. and YOSHITAKE, T. 2024. Unveiling a 72.5 GPa peak hardness in sustainable nanodiamond composite hard coatings via discharge energy control: a nanoindentation-Raman approach. Materials letters [online], 369, article number 136684. Available from: https://doi.org/10.1016/j.matlet.2024.136684

• Journal Article Type: Article
• Acceptance Date: May 19, 2024
• Online Publication Date: May 26, 2024
• Publication Date: Aug 15, 2024
• Deposit Date: May 30, 2024
• Publicly Available Date: May 30, 2024
• Journal: Materials letters
• Print ISSN: 0167-577X
• Electronic ISSN: 1873-4979
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 369
• Article Number: 136684
• DOI: https://doi.org/10.1016/j.matlet.2024.136684
• Keywords: Nanocomposites; Arc plasma; Hardness; Raman; Sustainable hard coatings; Discharge energy
• Public URL: https://rgu-repository.worktribe.com/output/2349228
• Additional Information: This article has been published with separate supporting information. This supporting information has been incorporated into a single file on this repository and can be found at the end of the file associated with this output.